Data transmission indication method, access point and terminal

ABSTRACT

The present invention provides a data transmission indication method, an access point and a terminal. The method includes: sending, by an access point, orthogonal frequency division multiple access (OFDMA) physical layer signaling to a terminal. The OFDMA physical layer signaling indicates, to the terminal, a subchannel allocated for the terminal, so that the terminal determines the subchannel according to the OFDMA physical layer signaling. The OFDMA physical layer signaling includes an identifier of the terminal and subchannel information corresponding to the identifier of the terminal. In the method provided in an embodiment of the present invention, a manner in which the access point allocates a subchannel for each terminal according to OFDMA physical layer signaling enables the access point to indicate subchannels for more terminals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2014/071689, filed on Jan. 28, 2014, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the field of communicationstechnologies, and in particular, to a data transmission indicationmethod, an access point and a terminal.

BACKGROUND

Orthogonal frequency division multiplexing (OFDM) is a basictransmission manner of current wireless communications, where in a rangeallowed by orthogonality of a subcarrier, a subcarrier interval iscompressed to minimum, thereby forming multiple transmission paths thatare parallel and do not interfere with each other, so as to improvefrequency utilization efficiency of a system. Features of the foregoingOFDM are used in orthogonal frequency division multiple access (OFDMA),and subcarriers in the OFDM that do not interfere with each other areallocated to multiple users, so as to implement multi-user access ordata transmission. Sending data in the OFDMA mode is actually: atransmitting end synchronously sends data of multiple receiving ends byusing subchannels corresponding to the receiving ends to the receivingends associated with the subchannels (a subchannel herein may includeone subcarrier, or may include multiple subcarriers).

In the prior art, transmission in an OFDMA mode can support only abandwidth of 20 MHz to perform transmission, and the 20 MHz may bedivided into 64 subcarriers, where 48 subcarriers are used fortransmitting user data. In a conventional OFDMA technology, a signalingpart (a format of the signaling part is only applicable to a bandwidthof 20 MHz) is added following a physical layer preamble in a dataformat, and the signaling part is used for indicating a user allocatedfor each subcarrier, where one subcarrier can only correspond to oneuser identity (ID). A transmitting end synchronously transmits data ofdifferent users on different subcarriers, and correspondingly, a userreceives, on a corresponding subcarrier, data sent by the transmittingend.

However, when a quantity of users is greater than 48, because of alimitation on the bandwidth of 20 MHz, an indication cannot be performedfor rest users beyond 48 users when the rest users receive data of atransmitting end in the prior art.

SUMMARY

The present invention provides a data transmission indication method, anaccess point and a terminal, which are used for resolving a problem inthe prior art that an indication cannot be performed for rest usersbeyond 48 users when the rest users receives data of a transmitting end.

According to a first aspect, the present invention provides a datatransmission indication method, including:

sending, by an access point, OFDMA physical layer signaling to aterminal, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel allocated for the terminal, sothat the terminal determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, where theOFDMA physical layer signaling includes an identifier of the terminaland subchannel information corresponding to the identifier of theterminal.

With reference to the first aspect, in a first possible implementationmanner of the first aspect, the identifier of the terminal is anidentifier of one or more terminal groups, and each terminal groupincludes at least one terminal; and the subchannel information includesan uplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, and then the OFDMA physical layer signalingbeing used for indicating, to the terminal, a subchannel allocated forthe terminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal group that the allocated subchannel is an uplink subchannel ora downlink subchannel or an uplink and downlink bidirectionalsubchannel, where the terminal group and the subchannel are in aone-to-one correspondence.

With reference to the first possible implementation manner of the firstaspect, in a second possible implementation manner of the first aspect,before the sending, by an access point, OFDMA physical layer signalingto a terminal, the method further includes:

sending, by the access point, a mapping relationship between anidentifier of the terminal group and an address of the terminal to theterminal, so that the terminal learns a terminal group in which theterminal is located.

With reference to the first aspect, in a third possible implementationmanner of the first aspect, the identifier of the terminal is anidentifier of one terminal group, and the terminal group includes atleast two terminals; and then the OFDMA physical layer signaling beingused for indicating, to the terminal, a subchannel allocated for theterminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where each terminal in the terminal group andthe subchannel are in a one-to-one correspondence.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a fourth possibleimplementation manner of the first aspect, the sending, by an accesspoint, OFDMA physical layer signaling to a terminal includes:

sending, by the access point, an OFDM preamble to the terminal, wherethe OFDM preamble carries the OFDMA physical layer signaling; or

sending, by the access point, a null data packet announcement (NDPA)frame to the terminal, where the NDPA frame carries the OFDMA physicallayer signaling.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a fifth possibleimplementation manner of the first aspect, the sending, by an accesspoint, OFDMA physical layer signaling to a terminal includes:

sending, by the access point, an NDPA frame and an OFDM preamble to theterminal,

where the NDPA frame carries the identifier of the terminal in the OFDMAphysical layer signaling, and the OFDM preamble carries the subchannelinformation corresponding to the identifier of the terminal and being inthe OFDMA physical layer signaling; or the NDPA frame carries thesubchannel information corresponding to the identifier of the terminaland being in the OFDMA physical layer signaling, and the OFDM preamblecarries the identifier of the terminal in the OFDMA physical layersignaling.

With reference to any one of the first aspect to the fifth possibleimplementation manner of the first aspect, in a sixth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, asubchannel that is allocated to the terminal for receiving downlinkOFDMA data information, and then after the sending, by an access point,OFDMA physical layer signaling to a terminal, the method furtherincludes:

sending, by the access point, downlink OFDMA data information on thesubchannel corresponding to the terminal in an OFDMA mode, where thedownlink OFDMA data information includes an OFDMA preamble and OFDMAdata, and the OFDMA preamble includes a switching field and ultra highthroughput signaling B (UHT-SIG-B).

With reference to the sixth possible implementation manner of the firstaspect, in a seventh possible implementation manner of the first aspect,the OFDMA physical layer signaling or the downlink OFDMA datainformation carries an OFDMA acknowledge (ACK) request or an OFDMA blockacknowledge (BA) request, and the OFDMA ACK request or the OFDMA BArequest is used for instructing the terminal to send an ACK response ora BA response to the access point in the OFDMA mode; then the OFDMAphysical layer signaling is further used for indicating the subchannelthat corresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then after the sending, by the access point, downlinkOFDMA data information on the subchannel corresponding to the terminalin an OFDMA mode, the method further includes:

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the subchannel corresponding to the terminalin the OFDMA mode.

With reference to the sixth possible implementation manner of the firstaspect, in an eighth possible implementation manner of the first aspect,the OFDMA physical layer signaling is used for indicating the subchannelthat corresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal, and then after the sending, by the access point, downlinkOFDMA data information on the subchannel corresponding to the terminal,the method further includes:

sending, by the access point, an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a ninth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thesending, by an access point, OFDMA physical layer signaling to aterminal includes:

sending, by the access point, multi-user multiple-input multiple-output(MU-MIMO) data information to the terminal in a MU-MIMO mode, where theMU-MIMO data information carries the OFDMA physical layer signaling; and

then after the sending, by an access point, OFDMA physical layersignaling to a terminal, the method further includes:

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a tenth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the sending, by an access point, OFDMA physicallayer signaling to a terminal includes:

sending, by the access point, MU-MIMO data information to the terminalin a MU-MIMO mode, where the MU-MIMO data information carries the OFDMAphysical layer signaling; and

sending, by the access point, an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in an OFDMA mode; and

then after the sending, by an access point, OFDMA physical layersignaling to a terminal, the method further includes:

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the subchannel corresponding to the terminalin the OFDMA mode.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in an eleventh possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the sending, by an access point, OFDMA physicallayer signaling to a terminal includes:

sending, by the access point, MU-MIMO data information to the terminalin a MU-MIMO mode,

sending, by the access point, an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in an OFDMA mode; and the ACK request frameor the BA request frame carries the OFDMA physical layer signaling; and

then after the sending, by an access point, OFDMA physical layersignaling to a terminal, the method further includes:

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a twelfth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and after thesending, by an access point, OFDMA physical layer signaling to aterminal, the method further includes:

sending, by the access point, OFDMA+MU-MIMO data information to theterminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode; and

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

With reference to any one of the first aspect to the third possibleimplementation manner of the first aspect, in a thirteenth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and after the sending, by an access point, OFDMA physicallayer signaling to a terminal, the method further includes:

sending, by the access point, OFDMA+MU-MIMO data information to theterminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode;

sending, by the access point, an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in an OFDMA mode; and

receiving, by the access point, the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

With reference to any one of the first aspect to the fifth possibleimplementation manner of the first aspect, in a fourteenth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then before the sending, by an access point, OFDMAphysical layer signaling to a terminal, the method further includes:

receiving, by the access point, an uplink transmission frame sent by theterminal; and

then after the sending, by an access point, OFDMA physical layersignaling to a terminal, the method further includes:

receiving, by the access point, the uplink OFDMA data information thatis sent by the terminal on the corresponding subchannel in an OFDMAmode.

With reference to the fourteenth possible implementation manner of thefirst aspect, in a fifteenth possible implementation manner of the firstaspect, the uplink OFDMA data information carries an OFDMA ACK requestor an OFDMA BA request, and the OFDMA ACK request or the OFDMA BArequest is further used for instructing the access point to send an ACKresponse or a BA response to the terminal in the OFDMA mode; and thenafter the receiving, by the access point, the uplink OFDMA datainformation that is sent by the terminal on the correspondingsubchannel, the method further includes:

sending, by the access point, the ACK response or the BA responsecorresponding to the uplink OFDMA data information on the subchannelcorresponding to the terminal in the OFDMA mode.

With reference to any one of the first aspect to the fifth possibleimplementation manner of the first aspect, in a sixteenth possibleimplementation manner of the first aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then after the sending, by an access point, OFDMA physicallayer signaling to a terminal, the method further includes:

receiving, by the access point, the uplink OFDMA data information thatis sent by the terminal on the corresponding subchannel in an OFDMAmode.

According to a second aspect, the present invention provides a datatransmission indication method, including:

receiving, by a terminal, OFDMA physical layer signaling sent by anaccess point, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel allocated by the access pointfor the terminal, where the OFDMA physical layer signaling includes anidentifier of the terminal and subchannel information corresponding tothe identifier of the terminal; and

determining, by the terminal, the subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

With reference to the second aspect, in a first possible implementationmanner of the second aspect, the identifier of the terminal is anidentifier of one or more terminal groups, and each terminal groupincludes at least one terminal; and the subchannel information includesan uplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, and then the OFDMA physical layer signalingbeing used for indicating, to the terminal, a subchannel allocated forthe terminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal group that the allocated subchannel is an uplink subchannel ora downlink subchannel or an uplink and downlink bidirectionalsubchannel, where the terminal group and the subchannel are in aone-to-one correspondence.

With reference to the first possible implementation manner of the secondaspect, in a second possible implementation manner of the second aspect,before the receiving, by a terminal, OFDMA physical layer signaling sentby an access point, the method further includes:

receiving, by the terminal, a mapping relationship between an identifierof the terminal group and an address of the terminal, where the mappingrelationship is sent by the access point; and

then the determining, by the terminal, the subchannel corresponding tothe terminal according to the OFDMA physical layer signaling includes:

determining, by the terminal, according to the mapping relationship thatthe terminal is located in the terminal group, and then determining, bythe terminal, that a subchannel corresponding to the terminal group isthe subchannel corresponding to the terminal.

With reference to the second aspect, in a third possible implementationmanner of the second aspect, the identifier of the terminal is anidentifier of one terminal group, and the terminal group includes atleast two terminals; and then the OFDMA physical layer signaling beingused for indicating, to the terminal, a subchannel allocated for theterminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where each terminal in the terminal group andthe subchannel are in a one-to-one correspondence.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a fourth possibleimplementation manner of the second aspect, the receiving, by aterminal, OFDMA physical layer signaling sent by an access pointincludes:

receiving, by the terminal, an OFDM preamble sent by the access point,where the OFDM preamble carries the OFDMA physical layer signaling; or

receiving, by the terminal, a NDPA frame sent by the access point, wherethe NDPA frame carries the OFDMA physical layer signaling.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a fifth possibleimplementation manner of the second aspect, the receiving, by aterminal, OFDMA physical layer signaling sent by an access point furtherincludes:

receiving, by the terminal, an NDPA frame and an OFDM preamble that aresent by the access point, where the NDPA frame carries the identifier ofthe terminal in the OFDMA physical layer signaling, and the OFDMpreamble carries the subchannel information corresponding to theidentifier of the terminal and being in the OFDMA physical layersignaling; or the NDPA frame carries the subchannel informationcorresponding to the identifier of the terminal and being in the OFDMAphysical layer signaling, and the OFDM preamble carries the identifierof the terminal in the OFDMA physical layer signaling.

With reference to any one of the second aspect to the fifth possibleimplementation manner of the second aspect, in a sixth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, asubchannel that is allocated by the access point to the terminal forreceiving downlink OFDMA data, and then after the determining, by theterminal, the subchannel corresponding to the terminal according to theOFDMA physical layer signaling, the method further includes:

receiving, by the terminal on the subchannel corresponding to theterminal, downlink OFDMA data information sent by the access point,where the downlink OFDMA data information includes an OFDMA preamble andOFDMA data, and the OFDMA preamble includes a switching field andUHT-SIG-B.

With reference to the sixth possible implementation manner of the secondaspect, in a seventh possible implementation manner of the secondaspect, the receiving, by the terminal on the subchannel correspondingto the terminal, downlink OFDMA data information sent by the accesspoint specifically includes:

receiving, by the terminal, a destination terminal address correspondingto the OFDMA data and sent by the access point;

determining, by the terminal, whether the terminal matches thedestination terminal address; and

if yes, receiving, by the terminal on the subchannel corresponding tothe terminal, the downlink OFDMA data information sent by the accesspoint.

With reference to the seventh possible implementation manner of thesecond aspect, in an eighth possible implementation manner of the secondaspect, the OFDMA physical layer signaling or the downlink OFDMA datainformation carries an OFDMA acknowledge (ACK) request or an OFDMA blockacknowledge (BA) request, and the OFDMA ACK request or the OFDMA BArequest is used for instructing the terminal to send an ACK response ora BA response to the access point in an OFDMA mode; and then the OFDMAphysical layer signaling is further used for indicating the subchannelthat corresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal, and then after the receiving, by the terminal on thesubchannel corresponding to the terminal, downlink OFDMA datainformation sent by the access point, the method further includes:

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to the seventh possible implementation manner of thesecond aspect, in a ninth possible implementation manner of the secondaspect, the OFDMA physical layer signaling is used for indicating thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal, and then after the receiving, by the terminal on thesubchannel corresponding to the terminal, downlink OFDMA datainformation sent by the access point, the method further includes:

receiving, by the terminal, an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; and

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a tenth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thereceiving, by a terminal, OFDMA physical layer signaling sent by anaccess point includes:

receiving, by the terminal, MU-MIMO data information sent by the accesspoint, where the MU-MIMO data information carries the OFDMA physicallayer signaling; and

then after the determining, by the terminal, the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, the method further includes:

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in an eleventh possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the receiving, by a terminal, OFDMA physicallayer signaling sent by an access point includes:

receiving, by the terminal, MU-MIMO data information sent by the accesspoint, where the MU-MIMO data information carries the OFDMA physicallayer signaling; and

receiving, by the terminal, an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; and

then after the determining, by the terminal, the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, the method further includes:

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a twelfth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the receiving, by a terminal, OFDMA physicallayer signaling sent by an access point includes:

receiving, by the terminal, MU-MIMO data information sent by the accesspoint,

receiving, by the terminal, an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; andthe ACK request frame or the BA request frame carries the OFDMA physicallayer signaling; and

then after the determining, by the terminal, the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, the method further includes:

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a thirteenth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then afterthe determining, by the terminal, the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, the methodfurther includes:

receiving, by the terminal on the subchannel corresponding to theterminal, OFDMA+MU-MIMO data information sent by the access point; and

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the third possibleimplementation manner of the second aspect, in a fourteenth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then after the determining, by the terminal, thesubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, the method further includes:

receiving, by the terminal on the subchannel corresponding to theterminal, OFDMA+MU-MIMO data information sent by the access point;

receiving, by the terminal, an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in an OFDMA mode; and

sending, by the terminal, the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

With reference to any one of the second aspect to the fifth possibleimplementation manner of the second aspect, in a fifteenth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then before thereceiving, by a terminal, OFDMA physical layer signaling sent by anaccess point, the method further includes:

sending, by the terminal, an uplink transmission frame to the accesspoint; and

then after the determining, by the terminal, the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, the method further includes:

sending, by the terminal, the uplink OFDMA data information to theaccess point on the subchannel corresponding to the terminal in an OFDMAmode.

With reference to the fifteenth possible implementation manner of thesecond aspect, in a sixteenth possible implementation manner of thesecond aspect, the uplink OFDMA data information carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is further used for instructing the access point to send anACK response or a BA response to the terminal in the OFDMA mode; andthen after the sending, by the terminal, the uplink OFDMA datainformation to the access point on the subchannel corresponding to theterminal, the method further includes:

receiving, by the terminal on the subchannel corresponding to theterminal, the ACK response or the BA response corresponding to theuplink OFDMA data information and sent by the access point.

With reference to any one of the second aspect to the fifth possibleimplementation manner of the second aspect, in a seventeenth possibleimplementation manner of the second aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then after the determining, by the terminal, thesubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, the method further includes:

sending, by the terminal, the uplink OFDMA data information to theaccess point on the subchannel corresponding to the terminal in an OFDMAmode.

According to a third aspect, the present invention provides an accesspoint, including:

a sending module, configured to send OFDMA physical layer signaling to aterminal, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel allocated for the terminal, sothat the terminal determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, where theOFDMA physical layer signaling includes an identifier of the terminaland subchannel information corresponding to the identifier of theterminal.

With reference to the third aspect, in a first possible implementationmanner of the third aspect, the identifier of the terminal is anidentifier of one or more terminal groups, and each terminal groupincludes at least one terminal; and the subchannel information includesan uplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, and then the OFDMA physical layer signalingbeing used for indicating, to the terminal, a subchannel allocated forthe terminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal group that the allocated subchannel is an uplink subchannel ora downlink subchannel or an uplink and downlink bidirectionalsubchannel, where the terminal group and the subchannel are in aone-to-one correspondence.

With reference to the first possible implementation manner of the thirdaspect, in a second possible implementation manner of the third aspect,the sending module is further configured to: before the OFDMA physicallayer signaling is sent to the terminal, send a mapping relationshipbetween an identifier of the terminal group and an address of theterminal to the terminal, so that the terminal learns a terminal groupin which the terminal is located.

With reference to the third aspect, in a third possible implementationmanner of the third aspect, the identifier of the terminal is anidentifier of one terminal group, and the terminal group includes atleast two terminals; and then the OFDMA physical layer signaling beingused for indicating, to the terminal, a subchannel allocated for theterminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where each terminal in the terminal group andthe subchannel are in a one-to-one correspondence.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a fourth possibleimplementation manner of the third aspect, the sending module isspecifically configured to send an OFDM preamble to the terminal, wherethe OFDM preamble carries the OFDMA physical layer signaling; orspecifically configured to send a NDPA frame to the terminal, where theNDPA frame carries the OFDMA physical layer signaling.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a fifth possibleimplementation manner of the third aspect, the sending module is furtherconfigured to send an NDPA frame and an OFDM preamble to the terminal,where the NDPA frame carries the identifier of the terminal in the OFDMAphysical layer signaling, and the OFDM preamble carries the subchannelinformation corresponding to the identifier of the terminal and being inthe OFDMA physical layer signaling; or the NDPA frame carries thesubchannel information corresponding to the identifier of the terminaland being in the OFDMA physical layer signaling, and the OFDM preamblecarries the identifier of the terminal in the OFDMA physical layersignaling.

With reference to any one of the third aspect to the fifth possibleimplementation manner of the third aspect, in a sixth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, asubchannel that is allocated to the terminal for receiving downlinkOFDMA data information, and then the sending module is furtherconfigured to: after the OFDMA physical layer signaling is sent to theterminal, send downlink OFDMA data information on the subchannelcorresponding to the terminal in an OFDMA mode, where the downlink OFDMAdata information includes an OFDMA preamble and OFDMA data, and theOFDMA preamble includes a switching field and ultra high throughputsignaling B (UHT-SIG-B).

With reference to the sixth possible implementation manner of the thirdaspect, in a seventh possible implementation manner of the third aspect,the OFDMA physical layer signaling or the downlink OFDMA datainformation carries an OFDMA acknowledge (ACK) request or an OFDMA blockacknowledge (BA) request, and the OFDMA ACK request or the OFDMA BArequest is used for instructing the terminal to send an ACK response ora BA response to the access point in the OFDMA mode; then the OFDMAphysical layer signaling is further used for indicating the subchannelthat corresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then the access point further includes:

a receiving module, configured to: after the sending module sends thedownlink OFDMA data information on the subchannel corresponding to theterminal in the OFDMA mode, receive the ACK response or the BA responsethat is sent by the terminal on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to the sixth possible implementation manner of the thirdaspect, in an eighth possible implementation manner of the third aspect,the OFDMA physical layer signaling is used for indicating the subchannelthat corresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then the sending module is further configured to: afterthe downlink OFDMA data information is sent on the subchannelcorresponding to the terminal, send an ACK request frame or a BA requestframe to the terminal, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; and

the receiving module is further configured to receive the ACK responseor the BA response that is sent by the terminal on the correspondingsubchannel in the OFDMA mode.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a ninth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thesending module is specifically configured to send MU-MIMO datainformation to the terminal in a MU-MIMO mode, where the MU-MIMO datainformation carries the OFDMA physical layer signaling; and

the receiving module is further configured to: after the sending modulesends the OFDMA physical layer signaling to the terminal, receive theACK response or the BA response that is sent by the terminal on thecorresponding subchannel in the OFDMA mode.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a tenth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the sending module is specifically configured tosend MU-MIMO data information to the terminal in a MU-MIMO mode, wherethe MU-MIMO data information carries the OFDMA physical layer signaling;and send an ACK request frame or a BA request frame to the terminal,where the ACK request frame or the BA request frame includes a dedicatedinformation bit, and the dedicated information bit is used forinstructing the terminal to send the ACK response or the BA response tothe access point in the OFDMA mode; and

then the receiving module is further configured to: after the sendingmodule sends the OFDMA physical layer signaling to the terminal, receivethe ACK response or the BA response that is sent by the terminal on thesubchannel corresponding to the terminal in the OFDMA mode.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in an eleventh possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the sending module is specifically configured tosend MU-MIMO data information to the terminal in a MU-MIMO mode, andsend an ACK request frame or a BA request frame to the terminal, wherethe ACK request frame or the BA request frame includes a dedicatedinformation bit, and the dedicated information bit is used forinstructing the terminal to send the ACK response or the BA response tothe access point in an OFDMA mode; and the ACK request frame or the BArequest frame carries the OFDMA physical layer signaling; and

then the receiving module is further configured to: after the sendingmodule sends the OFDMA physical layer signaling to the terminal, receivethe ACK response or the BA response that is sent by the terminal on thecorresponding subchannel in the OFDMA mode.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a twelfth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and the sendingmodule is further configured to: after the OFDMA physical layersignaling is sent to the terminal, send OFDMA+MU-MIMO data informationto the terminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode; and

the receiving module is further configured to receive the ACK responseor the BA response that is sent by the terminal on the correspondingsubchannel in the OFDMA mode.

With reference to any one of the third aspect to the third possibleimplementation manner of the third aspect, in a thirteenth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the sending module is further configured to:after the OFDMA physical layer signaling is sent to the terminal, sendOFDMA+MU-MIMO data information to the terminal on the subchannelcorresponding to the terminal in an OFDMA+MU-MIMO mode; and send an ACKrequest frame or a BA request frame to the terminal, where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin an OFDMA mode; and

then the receiving module is further configured to receive the ACKresponse or the BA response that is sent by the terminal on thecorresponding subchannel in the OFDMA mode.

With reference to any one of the third aspect to the fifth possibleimplementation manner of the third aspect, in a fourteenth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and

then the receiving module is further configured to: before the sendingmodule sends the OFDMA physical layer signaling to the terminal, receivean uplink transmission frame sent by the terminal; and after the sendingmodule sends the OFDMA physical layer signaling to the terminal, receivethe uplink OFDMA data information that is sent by the terminal on thecorresponding subchannel in an OFDMA mode.

With reference to the fourteenth possible implementation manner of thethird aspect, in a fifteenth possible implementation manner of the thirdaspect, the uplink OFDMA data information carries an OFDMA ACK requestor an OFDMA BA request, and the OFDMA ACK request or the OFDMA BArequest is further used for instructing the access point to send an ACKresponse or a BA response to the terminal in the OFDMA mode; and thenthe sending module is further configured to: after the receiving modulereceives the uplink OFDMA data information that is sent by the terminalon the corresponding subchannel, send the ACK response or the BAresponse corresponding to the uplink OFDMA data information on thesubchannel corresponding to the terminal in the OFDMA mode.

With reference to any one of the third aspect to the fifth possibleimplementation manner of the third aspect, in a sixteenth possibleimplementation manner of the third aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then the receiving module is further configured to: afterthe sending module sends the OFDMA physical layer signaling to theterminal, receive the uplink OFDMA data information that is sent by theterminal on the corresponding subchannel in an OFDMA mode.

According to a fourth aspect, the present invention provides a terminal,including:

a receiving module, configured to receive OFDMA physical layer signalingsent by an access point, where the OFDMA physical layer signaling isused for indicating, to the terminal, a subchannel allocated by theaccess point for the terminal, where the OFDMA physical layer signalingincludes an identifier of the terminal and subchannel informationcorresponding to the identifier of the terminal; and

a determining module, configured to determine the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling.

With reference to the fourth aspect, in a first possible implementationmanner of the fourth aspect, the identifier of the terminal is anidentifier of one or more terminal groups, and each terminal groupincludes at least one terminal; and the subchannel information includesan uplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, and then the OFDMA physical layer signalingbeing used for indicating, to the terminal, a subchannel allocated forthe terminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal group that the allocated subchannel is an uplink subchannel ora downlink subchannel or an uplink and downlink bidirectionalsubchannel, where the terminal group and the subchannel are in aone-to-one correspondence.

With reference to the first possible implementation manner of the fourthaspect, in a second possible implementation manner of the fourth aspect,the receiving module is further configured to: before the OFDMA physicallayer signaling sent by the access point is received, receive a mappingrelationship between an identifier of the terminal group and an addressof the terminal, where the mapping relationship is sent by the accesspoint; and then the determining module is specifically configured todetermine according to the mapping relationship that the terminal islocated in the terminal group, and then determine that a subchannelcorresponding to the terminal group is the subchannel corresponding tothe terminal.

With reference to the fourth aspect, in a third possible implementationmanner of the fourth aspect, the identifier of the terminal is anidentifier of one terminal group, and the terminal group includes atleast two terminals; and then the OFDMA physical layer signaling beingused for indicating, to the terminal, a subchannel allocated for theterminal includes:

the OFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where each terminal in the terminal group andthe subchannel are in a one-to-one correspondence.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a fourth possibleimplementation manner of the fourth aspect, the receiving module isspecifically configured to receive an OFDM preamble sent by the accesspoint, where the OFDM preamble carries the OFDMA physical layersignaling; or specifically configured to receive a NDPA frame sent bythe access point, where the NDPA frame carries the OFDMA physical layersignaling.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a fifth possibleimplementation manner of the fourth aspect, the receiving module isfurther configured to receive an NDPA frame and an OFDM preamble thatare sent by the access point, where the NDPA frame carries theidentifier of the terminal in the OFDMA physical layer signaling, andthe OFDM preamble carries the subchannel information corresponding tothe identifier of the terminal and being in the OFDMA physical layersignaling; or further configured to receive an NDPA frame and an OFDMpreamble that are sent by the access point, where the NDPA frame carriesthe subchannel information corresponding to the identifier of theterminal and being in the OFDMA physical layer signaling, and the OFDMpreamble carries the identifier of the terminal in the OFDMA physicallayer signaling.

With reference to any one of the fourth aspect to the fifth possibleimplementation manner of the fourth aspect, in a sixth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, asubchannel that is allocated by the access point to the terminal forreceiving downlink OFDMA data, and then the receiving module is furtherconfigured to: after the determining module determines the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, receive, on the subchannel corresponding to the terminal,downlink OFDMA data information sent by the access point, where thedownlink OFDMA data information includes an OFDMA preamble and OFDMAdata, and the OFDMA preamble includes a switching field and UHT-SIG-B.

With reference to the sixth possible implementation manner of the fourthaspect, in a seventh possible implementation manner of the fourthaspect, the receiving module includes:

a receiving unit, configured to receive a destination terminal addresscorresponding to the OFDMA data and sent by the access point; and

a determining unit, configured to determine whether the terminal matchesthe destination terminal address; and if yes, instruct the receivingunit to receive, on the subchannel corresponding to the terminal, thedownlink OFDMA data information sent by the access point.

With reference to the seventh possible implementation manner of thefourth aspect, in an eighth possible implementation manner of the fourthaspect, the OFDMA physical layer signaling or the downlink OFDMA datainformation carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; and then the OFDMA physical layer signaling is furtherused for indicating the subchannel that corresponds to the terminal, onwhich the ACK response or the BA response is sent to the access pointand that is allocated for the terminal, and then the terminal furtherincludes:

a sending module, configured to: after the receiving module receives, onthe subchannel corresponding to the terminal, the downlink OFDMA datainformation sent by the access point, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to the seventh possible implementation manner of thefourth aspect, in a ninth possible implementation manner of the fourthaspect, the OFDMA physical layer signaling is further used forindicating the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the receiving module is furtherconfigured to: after the downlink OFDMA data information sent by theaccess point is received on the subchannel corresponding to theterminal, receive an ACK request frame or a BA request frame sent by theaccess point, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in an OFDMA mode; and

then the sending module is further configured to send the ACK responseor the BA response to the access point on the subchannel correspondingto the terminal in the OFDMA mode.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a tenth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thereceiving module is specifically configured to receive MU-MIMO datainformation sent by the access point; and

the sending module is further configured to: after the determiningmodule determines the subchannel corresponding to the terminal accordingto the OFDMA physical layer signaling, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in an eleventh possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the receiving module is specifically configuredto receive MU-MIMO data information sent by the access point, where theMU-MIMO data information carries the OFDMA physical layer signaling; andreceive an ACK request frame or a BA request frame sent by the accesspoint, where the ACK request frame or the BA request frame includes adedicated information bit, and the dedicated information bit is used forinstructing the terminal to send the ACK response or the BA response tothe access point in an OFDMA mode; and

then the sending module is further configured to: after the determiningmodule determines the subchannel corresponding to the terminal accordingto the OFDMA physical layer signaling, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a twelfth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the receiving module is specifically configuredto receive MU-MIMO data information sent by the access point, andreceive an ACK request frame or a BA request frame sent by the accesspoint, where the ACK request frame or the BA request frame includes adedicated information bit, and the dedicated information bit is used forinstructing the terminal to send the ACK response or the BA response tothe access point in an OFDMA mode; and the ACK request frame or the BArequest frame carries the OFDMA physical layer signaling; and

then the sending module is further configured to: after the determiningmodule determines the subchannel corresponding to the terminal accordingto the OFDMA physical layer signaling, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a thirteenth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inan OFDMA mode; then the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, the subchannel that corresponds tothe terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thereceiving module is further configured to: after the determining moduledetermines the subchannel corresponding to the terminal according to theOFDMA physical layer signaling, receive, on the subchannel correspondingto the terminal, OFDMA+MU-MIMO data information sent by the accesspoint; and

the sending module is further configured to send the ACK response or theBA response to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to any one of the fourth aspect to the third possibleimplementation manner of the fourth aspect, in a fourteenth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the receiving module is further configured to:after the determining module determines the subchannel corresponding tothe terminal according to the OFDMA physical layer signaling, receive,on the subchannel corresponding to the terminal, OFDMA+MU-MIMO datainformation sent by the access point; and receive an ACK request frameor a BA request frame sent by the access point, where the ACK requestframe or the BA request frame includes a dedicated information bit, andthe dedicated information bit is used for instructing the terminal tosend the ACK response or the BA response to the access point in an OFDMAmode; and

the sending module is further configured to send the ACK response or theBA response to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

With reference to any one of the fourth aspect to the fifth possibleimplementation manner of the fourth aspect, in a fifteenth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the sendingmodule is further configured to: before the receiving module receivesthe OFDMA physical layer signaling sent by the access point, send anuplink transmission frame to the access point; and further configuredto: after the determining module determines the subchannel correspondingto the terminal according to the OFDMA physical layer signaling, sendthe uplink OFDMA data information to the access point on the subchannelcorresponding to the terminal in an OFDMA mode.

With reference to the fifteenth possible implementation manner of thefourth aspect, in a sixteenth possible implementation manner of thefourth aspect, the uplink OFDMA data information carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is further used for instructing the access point to send anACK response or a BA response to the terminal in the OFDMA mode; andthen the receiving module is further configured to: after the sendingmodule sends the uplink OFDMA data information to the access point,receive, on the subchannel corresponding to the terminal, the ACKresponse or the BA response corresponding to the uplink OFDMA datainformation and sent by the access point.

With reference to any one of the fourth aspect to the fifth possibleimplementation manner of the fourth aspect, in a seventeenth possibleimplementation manner of the fourth aspect, the OFDMA physical layersignaling is specifically used for indicating, to the terminal, thesubchannel that corresponds to the terminal, on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then the sending module is further configured to: afterthe determining module determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, send theuplink OFDMA data information to the access point on the subchannelcorresponding to the terminal in an OFDMA mode.

The present invention provides a data transmission indication method, anaccess point and a terminal, where an access point sends OFDMA physicallayer signaling to a terminal, so that each terminal learns a subchannelto which the terminal corresponds, and therefore the terminal mayperform a corresponding operation on the subchannel corresponding to theterminal. That is, a manner in which the access point allocates asubchannel for each terminal according to OFDMA physical layer signalingenables the access point to indicate subchannels for more terminals,that is, a quantity of terminals to which the access point indicatessubchannels is not limited.

BRIEF DESCRIPTION OF DRAWINGS

The following briefly introduces the accompanying drawings used indescribing the embodiments. Apparently, the accompanying drawings in thefollowing description show some embodiments of the present invention,and persons of ordinary skill in the art may still derive otherembodiments from these accompanying drawings without creative efforts.

FIG. 1 is a schematic flowchart of Embodiment 2 of a data transmissionindication method according to the present invention;

FIG. 2 is a schematic flowchart of Embodiment 4 of a data transmissionindication method according to the present invention;

FIG. 2a is a schematic diagram 1 of data transmission according to thepresent invention;

FIG. 2b is a schematic diagram 2 of data transmission according to thepresent invention;

FIG. 2c is a schematic diagram 3 of data transmission according to thepresent invention;

FIG. 2d is a schematic diagram 4 of data transmission according to thepresent invention;

FIG. 3 is a schematic flowchart of Embodiment 5 of a data transmissionindication method according to the present invention;

FIG. 3a is a schematic diagram 5 of data transmission according to thepresent invention;

FIG. 3b is a schematic diagram 6 of data transmission according to thepresent invention;

FIG. 4 is a schematic flowchart of Embodiment 6 of a data transmissionindication method according to the present invention;

FIG. 4a is a schematic diagram 7 of data transmission according to thepresent invention;

FIG. 4b is a schematic diagram 8 of data transmission according to thepresent invention;

FIG. 5 is a schematic flowchart of Embodiment 7 of a data transmissionindication method according to the present invention;

FIG. 6 is a schematic flowchart of Embodiment 8 of a data transmissionindication method according to the present invention;

FIG. 7 is a schematic flowchart of Embodiment 9 of a data transmissionindication method according to the present invention;

FIG. 8 is a schematic flowchart of Embodiment 10 of a data transmissionindication method according to the present invention;

FIG. 9 is a schematic flowchart of Embodiment 11 of a data transmissionindication method according to the present invention;

FIG. 10 is a schematic flowchart of Embodiment 12 of a data transmissionindication method according to the present invention;

FIG. 10a is a schematic diagram 9 of data transmission according to thepresent invention;

FIG. 10b is a schematic diagram 10 of data transmission according to thepresent invention;

FIG. 11 is a schematic flowchart of Embodiment 13 of a data transmissionindication method according to the present invention;

FIG. 11a is a schematic diagram 11 of data transmission according to thepresent invention;

FIG. 11b is a schematic diagram 12 of data transmission according to thepresent invention;

FIG. 12 is a schematic flowchart of Embodiment 14 of a data transmissionindication method according to the present invention;

FIG. 13 is a schematic flowchart of Embodiment 15 of a data transmissionindication method according to the present invention;

FIG. 14 is a schematic flowchart of Embodiment 17 of a data transmissionindication method according to the present invention;

FIG. 15 is a schematic flowchart of Embodiment 18 of a data transmissionindication method according to the present invention;

FIG. 16 is a schematic flowchart of Embodiment 19 of a data transmissionindication method according to the present invention;

FIG. 17 is a schematic flowchart of Embodiment 20 of a data transmissionindication method according to the present invention;

FIG. 18 is a schematic flowchart of Embodiment 21 of a data transmissionindication method according to the present invention;

FIG. 19 is a schematic flowchart of Embodiment 22 of a data transmissionindication method according to the present invention;

FIG. 20 is a schematic flowchart of Embodiment 23 of a data transmissionindication method according to the present invention;

FIG. 21 is a schematic flowchart of Embodiment 24 of a data transmissionindication method according to the present invention;

FIG. 22 is a schematic flowchart of Embodiment 25 of a data transmissionindication method according to the present invention;

FIG. 23 is a schematic flowchart of Embodiment 26 of a data transmissionindication method according to the present invention;

FIG. 24 is a schematic structural diagram of Embodiment 2 of an accesspoint according to the present invention;

FIG. 25 is a schematic structural diagram of Embodiment 1 of a terminalaccording to the present invention;

FIG. 26 is a schematic structural diagram of Embodiment 2 of a terminalaccording to the present invention;

FIG. 27 is a schematic structural diagram of Embodiment 3 of a terminalaccording to the present invention;

FIG. 28 is a block diagram of IDFT implementation in which an accesspoint sends downlink data information to a terminal in an OFDMA mode;

FIG. 29 is a schematic structural diagram of Embodiment 4 of an accesspoint according to the present invention;

FIG. 30 is a block diagram in which an access point implementstransmission of uplink OFDMA data information by using OFDMA physicallayer signaling;

FIG. 31 is a schematic structural diagram of Embodiment 4 of a terminalaccording to the present invention; and

FIG. 32 is a schematic structural diagram of Embodiment 5 of a terminalaccording to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are some but not all of the embodiments of thepresent invention. All other embodiments obtained by persons of ordinaryskill in the art based on the embodiments of the present inventionwithout creative efforts shall fall within the protection scope of thepresent invention.

A terminal involved in this application, that is, user equipment, may bea wireless terminal or a wired terminal. The wireless terminal may referto a device that provides a user with voice and/or data connectivity, ahandheld device with a radio connection function, or another processingdevice connected to a radio modem. The wireless terminal may communicatewith one or more core networks by using a radio access network (RAN).The wireless terminal may be a mobile terminal, such as a mobile phone(also referred to as a “cellular” phone) and a computer with a mobileterminal, for example, may be a portable, pocket-sized, handheld,computer built-in, or in-vehicle mobile apparatus, which exchangeslanguage and/or data with the radio access network. For example, it maybe a device such as a personal communication service (PCS) phone, acordless telephone set, a Session Initiation Protocol (SIP) phone, awireless local loop (WLL) station, or a personal digital assistant(PDA). The wireless terminal may also be referred to as a system, asubscriber unit, a subscriber station, a mobile station, a mobileterminal, a remote station, an access point, a remote terminal, anaccess terminal, a user terminal, a user agent, a user device, or userequipment.

An access point (such as a base station) involved in this applicationmay be an access point of a wireless local area network (WLAN), or mayrefer to a device communicating with a wireless terminal on an airinterface in an access network by using one or more sectors. The basestation may be used to mutually convert a received over-the-air frameand an IP packet and serve as a router between the wireless terminal anda rest portion of the access network, where the rest portion of theaccess network may include an Internet Protocol (IP) network. The basestation may also coordinate attribute management of the air interface.For example, the base station may be a base transceiver station (BTS) inGlobal System for Mobile communications (GSM) or code division multipleaccess (CDMA), may also be a base station (NodeB) in Wideband CDMA(WCDMA), and may further be an evolved NodeB (eNB, or e-NodeB) inLong-Term Evolution (LTE), which is not limited in this application.

Embodiment 1

Embodiment 1 of the present invention provides a data transmissionindication method. The method involved in the embodiment is a specificprocess in which an access point indicates a subchannel to which aterminal corresponds by using OFDMA physical layer signaling. The methodincludes: sending, by an access point, OFDMA physical layer signaling toa terminal, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel allocated for the terminal, sothat the terminal determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, where theOFDMA physical layer signaling includes an identifier of the terminaland subchannel information corresponding to the identifier of theterminal.

It should be noted that, there may be one or more terminals in thisembodiment of the present invention. The access point performs a sameoperation on each terminal, and therefore description is performed byusing a terminal in this embodiment of the present invention.

Specifically, the access point sends OFDMA physical layer signaling to aterminal in an OFDM mode, that is, the access point may send the OFDMAphysical layer signaling to a terminal in a coverage area of the accesspoint, but another terminal in the coverage area of the access point mayalso listen to obtain and correctly demodulate the OFDMA physical layersignaling. The OFDMA physical layer signaling in this embodiment of thepresent invention includes an identifier of the terminal and subchannelinformation corresponding to the identifier of the terminal, and is usedfor indicating, to the terminal, a subchannel allocated for theterminal, so that each terminal learns a subchannel corresponding to theterminal, and performs a corresponding operation on the subchannel, forexample, may receive, on the subchannel corresponding to the terminal,data that belongs to the terminal and is sent by the access point, ormay send corresponding response information or uplink data informationto the access point on the subchannel corresponding to the terminal. Theidentifier of the terminal in the foregoing OFDMA physical layersignaling may be an identifier of a single terminal group, or may beidentifiers of multiple terminal groups, and a terminal group mayinclude multiple terminals.

A channel bandwidth of a subchannel is not limited in the presentinvention, and the access point determines the bandwidth of thesubchannel according to a bandwidth requirement of a terminal. Moreover,the indicated subchannel may be presented in multiple forms, which maybe a center frequency and a bandwidth of the subchannel, or may be achannel number and a bandwidth of a start frequency band, or may be achannel number range from a start frequency band to an end frequencyband, which is not limited in the present invention.

A subchannel indicated by the OFDMA physical layer signaling involved inthis embodiment for a terminal may correspond to one terminal, or maycorrespond to multiple terminals. For example, multiple terminals may begrouped into one group, and the OFDMA physical layer signaling allocatesa subchannel for this group, and then all the terminals in the group mayuse the subchannel.

A format of a signaling part in the prior art can only support abandwidth of 20 MHz, and a user is allocated for each subcarrier for 48subcarriers; when a bandwidth greater than 20 MHz is used, the prior arthas no corresponding expansion solution to support the bandwidth.However, the OFDMA physical layer signaling in this embodiment of thepresent invention may support a larger bandwidth, and for a quantity ofterminals, allocate and indicate an allocated subchannel for multipleterminals, where the subchannel includes one or more subcarriers.Therefore, subjects for this embodiment of the present invention and theprior art are different (in the prior art, the subject is to allocateuser for a subcarrier, and in this embodiment of the present invention,the subject is to allocate a subchannel or a subcarrier for a user), theprior art can only perform indication for 48 terminals because of alimitation of subcarriers, and indicating, by OFDMA physical layersignaling, a subchannel for a terminal may be not limited by abandwidth, subchannels may be allocated for more terminals (users whosequantity exceeds 48) in a larger bandwidth. Certainly, this embodimentof the present invention may still allocate subchannels for terminalswhose quantity is less than 48.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling to a terminal, so that each terminal learns a subchannel towhich the terminal corresponds, and therefore the terminal may perform acorresponding operation on the subchannel corresponding to the terminal.That is, a manner in which the access point allocates a subchannel foreach terminal according to OFDMA physical layer signaling enables theaccess point to indicate subchannels for more terminals, that is, aquantity of terminals to which the access point indicates subchannels isnot limited.

Embodiment 2

FIG. 1 is a schematic flowchart of Embodiment 2 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a feasible implementation manner in whicha subchannel is indicated to a terminal by using OFDMA physical layersignaling. Further, on the basis of Embodiment 1, the identifier of theterminal may be an identifier of one or more terminal groups, eachterminal group includes at least one terminal, and the subchannelinformation includes an uplink subchannel or a downlink subchannel or anuplink and downlink bidirectional subchannel. The method includes:

S101: An access point sends a mapping relationship between an identifierof a terminal group and an address of a terminal to the terminal, sothat the terminal learns a terminal group in which the terminal islocated.

Specifically, the terminal needs to know a terminal group to which theterminal belongs, and then can know a subchannel corresponding to theterminal only when the access point allocates subchannels for theterminal group. Therefore, the access point needs to send a mappingrelationship between an identifier of a terminal group and an address ofa terminal to each terminal, so that each terminal learns a terminalgroup in which the terminal is located. For a simple manner in which aterminal is informed of a mapping relationship between an identifier ofa terminal group and an address of each terminal in a groupingmanagement frame form, reference may be made to Table 1, which isspecifically:

TABLE 1 Group 1 Group 2 . . . Group N Identifier Quantity Address . . .Address Identifier . . . . . . . . . Identifier . . . of the M of of ofof the of the N^(th) first terminals terminal terminal second groupgroup in a group 1 M group

By using a terminal grouping management frame shown in Table 1, aterminal may learn an identifier of a terminal group in which theterminal is located.

S102: The access point sends OFDMA physical layer signaling to theterminal, so that the terminal determines a subchannel corresponding tothe terminal according to the OFDMA physical layer signaling, where theOFDMA physical layer signaling includes an identifier of the terminaland subchannel information corresponding to the identifier of theterminal, and the OFDMA physical layer signaling is used for indicatingto each terminal group that the allocated subchannel is an uplinksubchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel.

Optionally, the OFDMA physical layer signaling may indicate by using adedicated indication bit that the subchannel allocated for the terminalis an uplink subchannel or a downlink subchannel or an uplink anddownlink bidirectional subchannel. That is, the foregoing OFDMA physicallayer signaling not only may indicate an allocated subchannel for theterminal group, but also may indicate, to the terminal group, that anallocated subchannel is an uplink subchannel or a downlink subchannel oran uplink and downlink bidirectional subchannel.

Specifically, the identifier of the terminal is an identifier of one ormore terminal groups, and the OFDMA physical layer signaling is used forindicating, to one or more terminal groups, a subchannel allocated foreach terminal group, where terminal groups and subchannels are in aone-to-one correspondence.

Related fields included in the indication of the foregoing OFDMAphysical layer signaling may be in a format shown in Table 2 below. Agroup number in Table 2 is used for indicating a grouping identifier ofcurrent multiple terminals, and the terminals may be stations (STAs). Afield shown in Table 2 may indicate that a subchannel is allocated foreach terminal group, and each terminal group herein may include at leastone terminal. For example, a terminal group 1 includes STA1 and STA2, aterminal group 2 includes STA3 to STA5, and a group n includes STA k toSTA n. According to this indication method, both STA1 and STA2 work on asubchannel 1, STA3 to STA5 work on a subchannel 2, and STA k to STA nall work on a subchannel n. By using this indication, a terminal maylearn a subchannel corresponding to the terminal, and the access pointmay also flexibly schedule a terminal in a terminal group on eachallocated subchannel. Additionally, terminal groups may have a commonelement, for example, the terminal group 1 includes STA1 to STA3, andthe terminal group 2 may include STA2 to STA5. Herein, STA2 and STA3 areboth in the terminal group 1 and the terminal group 2. In this manner,the access point may allocate, in an effective range of the indication,all subchannels for STAs flexibly, so as to further improve flexibilityof scheduling a terminal by the access point.

TABLE 2 Subchannel information Subchannel information of group 1 . . .of group n Group 1 Subchannel 1 . . . Group n Subchannel n

In another case, if in a subchannel, an interval between subcarriers inan OFDMA mode is different from an interval between subcarriers in anOFDM mode, and a special case is: the interval between the subcarriersin the OFDM mode is integer multiples (K multiples) of the intervalbetween the subcarriers in the OFDMA mode, effective indication onworking subchannels of multiple terminals may be implemented in a mannerin which subcarriers in the OFDMA mode are simply grouped. A quantity ofsubcarriers in the OFDM mode at each 20 MHz (that is, a unit subchannelbandwidth) is 64, and then a quantity of subcarriers in the OFDMA modeis 64*K (* is a product sign), and therefore the access point mayallocate 64*K subcarriers in a subchannel to terminals in a terminalgroup (refer to Table 3), that is, each terminal corresponds to several(one or more) subcarriers. That is, Table 3 is actually detailing ofTable 2 as far as a subchannel is concerned, where a subcarrier k_(n)may be a subcarrier identifier in the OFDMA mode (that is, k_(N)=64*K,and k_(n) may be any integer from 1 to k_(N)), or may be a subcarrieridentifier in the OFDM mode (that is, k_(N)=64). It should be notedthat, the prior art cannot support detailing on an interval betweensubcarriers, and therefore cannot perform indication for more users at20 MHz.

In a case in which the subcarrier k_(n) is a subcarrier identifier inthe OFDMA mode, an indication unit granularity of the method of thisembodiment is specific to each subcarrier of OFDMA (that is, asubcarrier may correspond to a terminal); in a case in which thesubcarrier k_(n) is a subcarrier identifier in the OFDM mode, anindication unit granularity of the method of this embodiment is Ksubcarriers of OFDMA. Therefore, the embodiment of the present inventionmethod may divide subchannels by using a narrower interval betweensubcarriers for a unit bandwidth (for example, the unit bandwidth is 20MHz), and implement effective indication on working subchannels ofmultiple terminals in a manner in which the divided subchannels aresimply grouped.

Additionally, when K=4, each 64 consecutive OFDMA subcarriers occupy achannel unit (5 MHz), and in this case, channel numbers in Embodiment 1and Embodiment 2 may also continue to be used as an indication manner.

TABLE 3 Subchannel information Subchannel information of group 1 . . .of group N Group 1 Subcarriers . . . Group N Subcarriers 1 to k₁k_(N−1) + 1 to k_(N)

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling carrying and including an identifier of a terminal andsubchannel information corresponding to the identifier of the terminalto the terminal, and the access point further sends a mappingrelationship between an identifier of a terminal group and an address ofeach terminal to each terminal, so that each terminal learns a terminalgroup in which the terminal is located, and further learns a subchannelcorresponding to the terminal, thereby performing a correspondingoperation on the subchannel. That is, a manner in which the access pointallocates a subchannel for each terminal according to OFDMA physicallayer signaling enables the access point to indicate subchannels formore terminals, that is, a quantity of terminals to which the accesspoint indicates subchannels is not limited.

Embodiment 3

Embodiment 3 of the present invention provides a data transmissionindication method. The method involved in this embodiment is anotherfeasible implementation manner in which an access point indicates asubchannel for a terminal by using OFDMA physical layer signaling. Onthe basis of Embodiment 1, the OFDMA physical layer signaling mayinclude an identifier of a terminal and subchannel informationcorresponding to the identifier of the terminal; and the identifier ofthe terminal is an identifier of a single terminal group, and theterminal group includes at least two terminals; and the OFDMA physicallayer signaling is used for indicating to each terminal in the terminalgroup that the allocated subchannel is an uplink subchannel or adownlink subchannel or an uplink and downlink bidirectional subchannel.

Optionally, the OFDMA physical layer signaling may indicate by using adedicated indication bit that the subchannel allocated for the terminalis an uplink subchannel or a downlink subchannel or an uplink anddownlink bidirectional subchannel. The terminals in the terminal groupand the subchannels are in a one-to-one correspondence. That is, theforegoing OFDMA physical layer signaling not only may indicate anallocated subchannel for each terminal in the terminal group, but alsomay indicate, to each terminal in the terminal group, that an allocatedsubchannel is an uplink subchannel or a downlink subchannel or an uplinkand downlink bidirectional subchannel.

Specifically, related fields included in the indication of the foregoingOFDMA physical layer signaling may be in a format shown in Table 4below. A group number in Table 4 is used for indicating a groupingidentifier of the current terminal group, and subchannels following thegroup number are and STAs in a terminal group corresponding to the groupnumber are in a one-to-one correspondence separately, that is, theaccess point allocates the subchannel to terminals in the terminal groupin sequence. That is, the STAs in the group corresponding to the groupnumber are STA1 to STAn in sequence; then according to the format, STA1corresponds to a subchannel 1, STA2 corresponds to a subchannel 2, untilSTA n corresponds to a subchannel n.

In the foregoing case in which an interval between subcarriers in asubchannel in the OFDM mode is different from that in the OFDMA mode, asubchannel allocated by each STA in a group not only may be indicated ina manner of only using a channel number or the like, but also may beindicated in a manner of using a subcarrier range, as shown in Table 4a.

TABLE 4 Group number Subchannel 1 Subchannel 2 . . . Subchannel n

TABLE 4a Group number Subcarriers Subcarriers . . . Subcarriers 1 to k₁k₁+ 1 to k₂ k_(N−1) + 1 to k_(N)

That is, each terminal in the foregoing terminal group corresponds to adifferent subchannel, and because the OFDMA physical layer signaling maysupport a larger bandwidth (not limited to a bandwidth of 20 MHz),subchannels may be indicated to more terminals.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling to a terminal, so that each terminal learns a subchannel towhich the terminal corresponds, and therefore the terminal may perform acorresponding operation on the subchannel corresponding to the terminal.That is, a manner in which the access point allocates a subchannel foreach terminal according to OFDMA physical layer signaling enables theaccess point to indicate subchannels for more terminals.

Embodiment 4

FIG. 2 is a schematic flowchart of Embodiment 4 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an OFDM preamblecarrying OFDMA physical layer signaling is sent to a terminal, so thatthe terminal learns a subchannel corresponding to the terminal accordingto the OFDMA physical layer signaling, and receives, on the subchannelcorresponding to the terminal, downlink OFDMA data information sent byan access point. The method includes:

S201: An access point sends an OFDM preamble to a terminal, where theOFDM preamble carries OFDMA physical layer signaling.

Specifically, the access point sends an OFDM preamble in an OFDM mode toany terminal in a coverage area of the access point, where the OFDMpreamble includes a short training field (STF), a long training field(LTF), a legacy signaling (L-SIG), and ultra high throughput signaling A(UHT-SIG-A), and the UHT-SIG-A carries OFDMA physical layer signaling.It should be noted that, the OFDM mode is: the access point sends anOFDM preamble to a terminal, but in this case, the access point does notknow the specific terminal to which the OFDM preamble is sent; thereforethe access point sends the OFDM preamble to any terminal, and all activeterminals listen to and receive the OFDM preamble, and then obtain OFDMAphysical layer signaling, thereby learning channels corresponding to theterminals.

It should be noted that, for a manner in which OFDMA physical layersignaling indicates a subchannel in this embodiment of the presentinvention, reference may be made to the description in Embodiment 1 toEmbodiment 3, and details are not described herein again in thisembodiment of the present invention.

S202: The access point sends downlink OFDMA data information on thesubchannel corresponding to the terminal in an OFDMA mode, where thedownlink OFDMA data information includes: an OFDMA preamble and OFDMAdata symbol; and the OFDMA preamble includes a switching field, andultra high throughput signaling B (UHT-SIG-B).

Specifically, the access point sends the downlink OFDMA data informationon the subchannel corresponding to the terminal in the OFDMA mode, thatis, the access point may send the downlink OFDMA data information tomultiple terminals on respective subchannels corresponding to theterminals at the same time, and therefore signaling overheads can bereduced and a multi-user diversity gain can be brought about.Additionally, the subchannel corresponding to the terminal may furtherinclude a primary channel of a basic service set (BSS), where theprimary channel is used by the access point and the terminal to exchangecontrol signaling and management signaling; that is, after sending theOFDMA physical layer signaling on the primary channel completely, theaccess point may release the primary channel; or may send the downlinkOFDMA data information to the terminal by using the primary channeltogether with another subchannel.

For a data transmission frame format of the OFDM preamble and thedownlink OFDMA data information, reference may be made to Table 5 below.Moreover, when being sent together, both the OFDMA physical layersignaling and the OFDMA data may use a format in Table 5; if only theOFDMA physical layer signaling is sent individually, only the OFDMpreamble is sent.

TABLE 5 Downlink OFDMA data information OFDM preamble part part STF LTFL- UHT-SIG-A Switching UHT-SIG-B Data SIG Field Symbol

It should be noted that, content transmitted in the OFDMA mode isindependent from each other for each terminal, that is, SwitchingFields, UHT-SIG-B and OFDMA data on respective subchannels correspondingto terminals are all independent from each other. The foregoingSwitching Field may include an ultra high throughput short trainingfield (UHT-STF) and an ultra high throughput long training field(UHT-LTF). In the OFDMA mode, the UHT-STF is used by the terminal tocomplete automatic gain control (AGC) or channel synchronization of asubchannel indicated by OFDMA physical layer signaling or all channels.The UHT-LTF is used by the terminal to complete channel estimation on asubchannel or all channels. If physical layer signaling in the UHT-SIG-Aonly performs channel allocation on a terminal group, the UHT-SIG-B maybe used by a transmitting end to perform further indication on aterminal in a terminal group corresponding to a subchannel in the subchannel.

If in an OFDMA+MU-MIMO mode, the UHT-STF is used by the terminal toperform AGC or channel synchronization on a subchannel indicated byOFDMA physical layer signaling or all channels and correspondingspace-time streams, the UHT-LTF is used by the terminal to performchannel estimation on a subchannel indicated by OFDMA physical layersignaling or all channels and subchannels of corresponding space-timestreams. Moreover, space-time stream allocation information of MU-MIMOmay be carried in the UHT-SIG-A, or may be carried in the UHT-SIG-B.

Additionally, the access point may send an OFDM preamble on the primarychannel in the OFDM mode (refer to an example in FIG. 2a ), or may sendan OFDM preamble on multiple subchannels in a repetitive manner (referto an example in FIG. 2b ). Then, the access point is switched to theOFDMA mode, and sends an OFDMA preamble and OFDMA data to the terminalon the foregoing indicated subchannel. On the other hand, in a case inwhich an interval between subcarriers of OFDM is different from that ofOFDMA (an example in which a unit channel is 20 MHz is used), for thesending, by the access point, the OFDM preamble and the downlink OFDMAdata information, reference may be made to an example in FIG. 2c , thatis, this unit channel (which is a primary channel in the figure) isdivided into multiple subcarriers, and one or more subcarrierscorrespond to a terminal; in a case in which an interval betweensubcarriers of OFDM is different from that of OFDMA, and a bandwidth isa sum of bandwidths of multiple unit channels, for the sending, by theaccess point, the OFDM preamble and the downlink OFDMA data information,reference may be made to an example in FIG. 2 d.

Correspondingly, the terminal detects and receives the OFDM preamble inan idle state and in the OFDM mode, and after receiving the OFDMpreamble in the OFDM mode (the OFDM preamble may be received on theprimary channel, or may be received on multiple subchannels), theterminal reads the OFDMA physical layer signaling in the UHT-SIG-A inthe OFDM manner; and is switched to the subchannel indicated by theOFDMA physical layer signaling, adjusts AGC again, completes estimationon channel state information of the corresponding subchannel, anddemodulates the downlink OFDMA data information on the correspondingsubchannel, to obtain the OFDMA preamble and the OFDMA data that belongto the terminal.

Another receiving method of the terminal is: the terminal detects andreceives the OFDM preamble in an idle state and in the OFDM mode, andafter receiving the OFDM preamble in the OFDM mode (the OFDM preamblemay be received on the primary channel, or may be received on multiplesubchannels), the terminal reads the OFDMA physical layer signaling inthe UHT-SIG-A in the OFDM manner; and is switched to an entire bandwidthoccupied this time the access point sends data, adjusts AGC again,completes estimation on channel state information of the subchannelindicated by the OFDMA physical layer signaling or estimation on channelstate information of the entire bandwidth, and demodulates the downlinkOFDMA data information on the corresponding subchannel, to obtain theOFDMA preamble and the OFDMA data that belong to the terminal.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends an OFDM preamblecarrying OFDMA physical layer signaling to a terminal, so that theterminal may obtain OFDMA physical layer signaling from the OFDMpreamble, thereby learning, according to the OFDMA physical layersignaling, a subchannel on which the terminal should receive downlinkOFDMA data information corresponding to the terminal. That is, a mannerin which the access point allocates a subchannel for each terminalaccording to OFDMA physical layer signaling enables the access point toperform an indication for more terminals when receiving data of theaccess point, that is, a quantity of terminals to which the access pointindicates subchannels is not limited.

Embodiment 5

FIG. 3 is a schematic flowchart of Embodiment 5 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsa null data packet announcement (NDPA) frame carrying OFDMA physicallayer signaling to a terminal, so that the terminal obtains the OFDMAphysical layer signaling from the NDPA frame, and therefore the terminallearns a subchannel corresponding to the terminal according to the OFDMAphysical layer signaling, and receives, on the subchannel correspondingto the terminal, downlink OFDMA data information sent by an accesspoint. The method includes:

S301: An access point sends an NDPA frame to a terminal, where the NDPAframe carries the foregoing OFDMA physical layer signaling.

Specifically, an exclusive NDPA frame is used in this embodiment of thepresent invention to carry OFDMA physical layer signaling, and is usedfor reducing overheads brought about when the OFDMA physical layersignaling is transmitted. A format of the NDPA frame in this embodimentof the present invention is shown in Table 6, which is specifically:

TABLE 6 Frame Time Terminal Access Control Information . . . InformationFrame control length address point information about user about usererror address (group) 1 (group) n correction sequence

It should be noted that, the access point may send an NDPA frame to aterminal in a coverage area of the access point in an OFDM mode, and maysend the NDPA frame on a subchannel (such as a primary channel) (referto an example in FIG. 3a ), or may send the NDPA frame on multiplesubchannels (refer to an example in FIG. 3b ), and all other terminalsmay listen to obtain the NDPA frame. Then, the access point furtherneeds to send an OFDM preamble in the OFDM mode. The foregoing OFDMAphysical layer signaling may be carried in the NDPA frame, or may becarried in both the NDPA frame and the OFDM preamble, but is generallyonly carried in the NDPA frame to reduce signaling overheads.Optionally, when the NDPA frame carries the OFDMA physical layersignaling, the OFDM preamble may further indicate a specific terminalidentifier in a terminal group.

It should be noted that, for a manner in which OFDMA physical layersignaling indicates a subchannel in this embodiment of the presentinvention, reference may be made to the description in Embodiment 1 toEmbodiment 3, and details are not described herein again in thisembodiment of the present invention.

S302: The access point sends downlink OFDMA data information on thesubchannel corresponding to the terminal in an OFDMA mode, where thedownlink OFDMA data information includes: an OFDMA preamble and OFDMAdata; and the OFDMA preamble includes a switching field and UHT-SIG-B.

Specifically, the access point sends the downlink OFDMA data informationin the OFDMA mode, that is, the access point may send the downlink OFDMAdata information to multiple terminals on respective subchannelscorresponding to terminals at the same time, and therefore correspondingtime frequency resources may be fully used.

Correspondingly, the terminal detects and receives the NDPA frame in theOFDM manner in an idle state, and reads the OFDMA physical layersignaling in the OFDM manner; and then the terminal also receives theOFDM preamble in the OFDM manner; and is switched to the OFDMA mode byusing the subchannel indicated by the OFDMA physical layer signaling,and receives, on the subchannel, the OFDMA preamble and the OFDMA datathat are sent by the access point in the OFDMA mode.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends an NDPA frame carryingOFDMA physical layer signaling to a terminal, so that the terminal mayobtain OFDMA physical layer signaling from the NDPA frame, therebylearning, according to the OFDMA physical layer signaling, a subchannelon which the terminal should receive downlink OFDMA data informationcorresponding to the terminal, so as to receive, on the correspondingsubchannel, the downlink OFDMA data information sent by the accesspoint. That is, a manner in which the access point allocates asubchannel for each terminal according to OFDMA physical layer signalingenables the access point to perform an indication for more terminalswhen receiving data of the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited. Additionally, the access point may send the downlink OFDMA datainformation to multiple terminals on respective subchannelscorresponding to terminals at the same time, and therefore correspondingtime frequency resources may be fully used.

Embodiment 6

FIG. 4 is a schematic flowchart of Embodiment 6 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsan NDPA frame and an OFDM preamble separately carrying content includedin OFDMA physical layer signaling to a terminal, so that the terminalobtains the OFDMA physical layer signaling from the NDPA frame and theOFDM preamble, and therefore the terminal learns a subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, and receives, on the subchannel corresponding to theterminal, downlink OFDMA data information sent by an access point. Themethod includes:

S401: An access point sends an NDPA frame and an OFDM preamble to aterminal.

Specifically, the NDPA frame and the OFDM preamble may carry the OFDMAphysical layer signaling in two cooperative manners, which areseparately:

First manner: An access point sends an NDPA frame and an OFDM preambleto a terminal, where the NDPA frame carries an identifier of theterminal in the foregoing OFDMA physical layer signaling, and the OFDMpreamble carries subchannel information corresponding to the identifierof the terminal and being in the foregoing OFDMA physical layersignaling. The identifier of the terminal herein may be an identifier ofone or more terminal groups in Embodiment 2, and subchannels andterminal groups are in a one-to-one correspondence; and may be furtheran identifier of a single terminal group in Embodiment 3, andsubchannels and terminals in the group are in a one-to-onecorrespondence.

Second manner: An access point sends an NDPA frame and an OFDM preambleto a terminal, where the NDPA frame carries subchannel informationcorresponding to an identifier of the terminal and being in theforegoing OFDMA physical layer signaling, and the OFDM preamble carriesthe identifier of the terminal in the foregoing OFDMA physical layersignaling. The identifier of the terminal herein may be an identifier ofone or more terminal groups in Embodiment 2, and subchannels andterminal groups are in a one-to-one correspondence; and may be furtheran identifier of a single terminal group in Embodiment 3, andsubchannels and terminals in the group are in a one-to-onecorrespondence.

That is, the NDPA frame and the OFDM preamble may cooperate with eachother to indicate the OFDMA physical layer signaling. A user groupinformation field in Table 5 may include the identifier of the terminal,and may further include the subchannel information corresponding to theidentifier of the terminal. Additionally, a control information field ofTable 5 may further indicate an effective time length of subchannelinformation of a currently indicated terminal or terminal group, so thatthe terminal can determine according to the time length whether theindication of the subchannel information of the terminal or terminalgroup is valid or expired, and if not expired, the terminal may continueto use the current subchannel to receive and send data.

If the NDPA frame carries the identifier of the terminal and thesubchannel information corresponding to the identifier of the terminal(that is, carries complete OFDMA physical layer signaling), the OFDMpreamble may not carry the identifier of the terminal or the subchannelinformation corresponding to the identifier of the terminal again (theOFDM preamble may also carry the OFDMA physical layer signaling,specific explanation has been described in the foregoing embodiment, anddetails are not described herein again); or if the NDPA frame onlycarries the identifier of the terminal, the OFDM preamble further needsto carry the subchannel information corresponding to the identifier ofthe terminal and being in the NDPA frame; or if the NDPA frame onlycarries the subchannel information, the OFDM preamble further needs tocarry the identifier of the terminal corresponding to the subchannelinformation and being in the NDPA frame.

It should be noted that, for a manner in which OFDMA physical layersignaling indicates a subchannel in this embodiment of the presentinvention, reference may be made to the description in Embodiment 1 toEmbodiment 3, and details are not described herein again in thisembodiment of the present invention.

S402: The access point sends downlink OFDMA data information on thesubchannel corresponding to the terminal in an OFDMA mode, where thedownlink OFDMA data information includes: an OFDMA preamble and OFDMAdata; and the OFDMA preamble includes a switching field (SwitchingField) and UHT-SIG-B.

Specifically, the access point sends the downlink OFDMA data informationin the OFDMA mode, that is, the access point may send the downlink OFDMAdata information to multiple terminals on respective subchannelscorresponding to terminals at the same time, and therefore correspondingtime frequency resources may be fully used.

Correspondingly, the terminal receives the NDPA frame in the OFDM mannerin an idle state, and reads a part of the OFDMA physical layer signalingcarried in the NDPA frame in the OFDM manner; then the terminal alsoreceives the OFDM preamble in the OFDM manner, and then reads that partof content that is supplemented for the OFDMA physical layer signalingand in the OFDM preamble; and then is switched, according to asubchannel indicated by the OFDMA physical layer signaling obtained bycombining the NDPA frame and the OFDM preamble, to the OFDMA mode toread/demodulate the OFDMA preamble and the OFDMA data of the terminal onthe subchannel corresponding to the terminal.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends an NDPA frame and anOFDM preamble that carry OFDMA physical layer signaling to a terminal,so that each terminal may learn, by using the NDPA frame and the OFDMpreamble, a subchannel on which the terminal should receive downlinkOFDMA data information corresponding to the terminal, so as to receivethe downlink OFDMA data information sent by the access point. That is, amanner in which the access point allocates a subchannel for eachterminal according to OFDMA physical layer signaling enables the accesspoint to perform an indication for more terminals when receiving data ofthe access point, that is, a quantity of terminals to which the accesspoint indicates subchannels is not limited. Additionally, the accesspoint may send the downlink OFDMA data information to multiple terminalson respective subchannels corresponding to terminals at the same time,and therefore corresponding time frequency resources may be fully used.

Further, on the basis of the embodiments shown in FIG. 2 to FIG. 4, as afeasible implementation manner of the embodiments of the presentinvention, the method involved in this embodiment is a process in whichafter sending downlink OFDMA data information to a terminal, an accesspoint receives an ACK response or a BA response that is sent by theterminal on a corresponding subchannel. Optionally, the foregoing OFDMAphysical layer signaling or OFDMA data carries an OFDMA ACK request oran OFDMA BA request, and the OFDMA ACK request or the OFDMA BA requestis used for instructing the terminal to send an ACK response or a BAresponse to the access point in an OFDMA mode; and then the foregoingOFDMA physical layer signaling is further used for indicating thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal. After S202 or S302 or S402, an operation of S10 may beperformed:

S10: The access point receives the ACK response or the BA response thatis sent by the terminal on the subchannel corresponding to the terminalin the OFDMA mode.

Specifically, to indicate that the downlink OFDMA data information sentby the access point is correctly received by each terminal, eachterminal needs to reply to the access point with an ACK response or a BAresponse. If the access point adds the OFDMA ACK request or OFDMA BArequest to the OFDMA data or OFDMA physical layer signaling (referringto FIG. 4a , an example in which the access point adds the OFDMA ACKrequest is used), after receiving the downlink OFDMA data information onthe subchannel corresponding to the terminal according to the indicationof the OFDMA physical layer signaling of the access point, the terminalmay directly reply with an ACK or BA response in the OFDMA mode on thesubchannel indicated by the OFDMA physical layer signaling. The ACKresponse corresponds to the OFDMA ACK request, and the BA responsecorresponds to the OFDMA BA request. Then, the access point receives ACKresponses or BA responses that are sent by terminals on respectivecorresponding subchannels. That is, multiple terminals are enabled tosend responses to the access point on subchannels corresponding to theterminals at the same time, and corresponding time frequency resourcesare fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives, on a subchannel indicatedby OFDMA physical layer signaling, downlink OFDMA data information sentby an access point, and multiple terminals may send ACK responses or BAresponses to the access point at the same time on correspondingsubchannels, that is, a manner in which the access point allocates asubchannel for each terminal according to OFDMA physical layer signalingenables the access point to perform an indication for more terminalswhen sending ACK responses or BA responses to the access point, that is,a quantity of terminals to which the access point indicates subchannelsis not limited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Further, on the basis of the embodiments shown in FIG. 2 to FIG. 4, asanother feasible implementation manner of the embodiments of the presentinvention, the method involved in this embodiment is a process in whichafter sending OFDMA physical layer signaling and downlink OFDMA datainformation to a terminal, an access point sends a single ACK requestframe or BA request frame to the terminal, so that the terminal can sendan ACK response or a BA response to the access point on a subchannelindicated by the OFDMA physical layer signaling.

The foregoing OFDMA physical layer signaling may be further used forindicating the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal. After S202 or S302 or S402, the followingsteps may be performed:

S20: An access point sends an ACK request frame or a BA request frame toa terminal, where the ACK request frame or the BA request frame includesa dedicated information bit, and the dedicated information bit is usedfor instructing the terminal to send the ACK response or the BA responseto the access point in the OFDMA mode.

Specifically, after sending the downlink OFDMA data information to theterminal, the access point may further send a single ACK request frameor BA request frame to the terminal (referring to FIG. 4b , an examplein which a BA request frame is individually sent is used), where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode. Optionally, the ACK request frame or the BA requestframe may carry the OFDMA physical layer signaling, or may not carry theOFDMA physical layer signaling. The terminal determines, according tothe OFDMA physical layer signaling, a subchannel on which the terminalsends the ACK response or the BA response to the access point. If theACK request frame or the BA request frame does not carry the OFDMAphysical layer signaling, the terminal replies with an ACK response or aBA response on a subchannel corresponding to each terminal when theaccess point sends downlink OFDMA data, that is, the terminal may use asubchannel on which the terminal receives the downlink OFDMA datainformation as a subchannel on which the terminal replies with the ACKresponse or BA response.

Representation of the dedicated information bit may be to identify theACK request frame or the BA request frame as a frame type used forinstructing the terminal to send an ACK response or a BA response to theaccess point in the OFDMA mode (that is, a new frame type different froma conventional ACK request frame or BA request frame). Representation ofanother dedicated information bit may also be: in a case in which aframe type of the ACK request frame or BA request frame is not changed,the dedicated information bit is directly used for instructing theterminal to send an ACK response or a BA response to the access point inthe OFDMA mode.

Additionally, similar to the OFDM preamble, the ACK request frame or BArequest frame may be sent only on the primary channel, or may be sent onall subchannels in a duplicated transmission manner.

S21: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding sub channel in the OFDMAmode.

Specifically, after learning, according to the OFDMA physical layersignaling, the subchannel on which the terminal sends the ACK responseor BA response to the access point, the terminal sends the ACK responseor BA response to the access point on the corresponding subchannel inthe OFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and corresponding timefrequency resources are fully used.

Optionally, if the subchannel of the terminal is multiple unit channels(such as, channels whose unit is 20 MHz), the terminal may send an ACKresponses or a BA responses on these multiple unit channels in theduplicated transmission manner, or may send an ACK responses or a BAresponses in a non-duplicated transmission manner.

In the data transmission indication method provided in this embodimentof the present invention, a subchannel on which an ACK response or a BAresponse is sent to an access point is indicated to a terminal by usingOFDMA physical layer signaling sent by the access point. That is, amanner in which the access point allocates a subchannel for eachterminal according to OFDMA physical layer signaling enables the accesspoint to perform an indication for more terminals when sending ACKresponses or BA responses to the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 7

FIG. 5 is a schematic flowchart of Embodiment 7 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsMU-MIMO data information carrying OFDMA physical layer signaling to aterminal, and an OFDMA ACK request or an OFDMA BA request is carried inthe OFDMA physical layer signaling, so that the terminal replies with anACK response or a BA response on a subchannel corresponding to theterminal in an OFDMA mode. As shown in FIG. 5, the method includes:

S501: An access point sends MU-MIMO data information to a terminal in aMU-MIMO mode, where the MU-MIMO data information carries OFDMA physicallayer signaling.

Specifically, the OFDMA physical layer signaling carried in theforegoing MU-MIMO data information includes an OFDMA ACK request orOFDMA BA request, used for instructing the terminal to send an ACKresponse or a BA response to the access point in the OFDMA mode, thatis, the access point requests the terminal to reply with an ACK responseor a BA response after the terminal obtains the corresponding MU-MIMOdata information. The OFDMA physical layer signaling is used forindicating, to the terminal, the subchannel on which the ACK response orthe BA response is sent to the access point and that is allocated forthe terminal.

S502: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding sub channel in an OFDMAmode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, an access point adds OFDMA physical layersignaling to MU-MIMO data information sent to a terminal, where theOFDMA physical layer signaling is used for indicating, to the terminal,a subchannel that sends an ACK response or a BA response to the accesspoint and is allocated for the terminal, so that terminals may send ACKresponses or BA responses to the access point on correspondingsubchannels at the same time, that is, a manner in which the accesspoint allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to perform anindication for more terminals when sending ACK responses or BA responsesto the access point, that is, a quantity of terminals to which theaccess point indicates subchannels is not limited, and therefore ACKresponses or BA responses of multiple terminals are transmitted to theaccess point in parallel, and corresponding time frequency resources arefully used.

Embodiment 8

FIG. 6 is a schematic flowchart of Embodiment 8 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsMU-MIMO data information carrying OFDMA physical layer signaling to aterminal, and sends an ACK request frame or a BA request frame to theterminal, so that the terminal replies with an ACK response or a BAresponse on a subchannel corresponding to the terminal in an OFDMA mode.As shown in FIG. 6, the method includes:

S601: An access point sends MU-MIMO data information to a terminal in aMU-MIMO mode, where the MU-MIMO data information carries OFDMA physicallayer signaling.

Specifically, the OFDMA physical layer signaling is used for indicating,to the terminal, the subchannel on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal.

S602: The access point sends an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode.

Specifically, the ACK request frame or the BA request frame sent by theaccess point to the terminal has an objective that lies in that theaccess point requests the terminal to reply to the access point with anACK response or a BA response to the terminal in the OFDMA mode afterthe terminal obtains corresponding MU-MIMO data information, so as tolearn whether the MU-MIMO data information is transmitted successfully.

S603: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in the OFDMAmode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, an access point adds OFDMA physical layersignaling to MU-MIMO data information sent to a terminal, where theOFDMA physical layer signaling is used for indicating, to the terminal,a subchannel that sends an ACK response or a BA response to the accesspoint and is allocated for the terminal, so that terminals may send ACKresponses or BA responses to the access point on correspondingsubchannels at the same time, that is, a manner in which the accesspoint allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to perform anindication for more terminals when sending ACK responses or BA responsesto the access point, that is, a quantity of terminals to which theaccess point indicates subchannels is not limited, and therefore ACKresponses or BA responses of multiple terminals are transmitted to theaccess point in parallel, and corresponding time frequency resources arefully used.

Embodiment 9

FIG. 7 is a schematic flowchart of Embodiment 9 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsan ACK request frame or a BA request frame carrying OFDMA physical layersignaling to a terminal, so that the terminal replies with an ACKresponse or a BA response on a subchannel corresponding to the terminalin an OFDMA mode. As shown in FIG. 7, the method includes:

S701: An access point sends MU-MIMO data information to a terminal in aMU-MIMO mode.

S702: The access point sends an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and the ACK requestframe or the BA request frame carries the OFDMA physical layersignaling.

Specifically, the ACK request frame or the BA request frame sent by theaccess point to the terminal has an objective that lies in that theaccess point requests the terminal to reply to the access point with anACK response or a BA response to the terminal in the OFDMA mode afterthe terminal obtains corresponding MU-MIMO data information, so as tolearn whether the MU-MIMO data information is transmitted successfully.The OFDMA physical layer signaling carried in the ACK request frame orthe BA request frame is used for indicating, to the terminal, thesubchannel on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal.

S703: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding sub channel in the OFDMAmode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, an access point adds OFDMA physical layersignaling to an ACK request frame or a BA request frame sent to aterminal, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel that sends an ACK response ora BA response to the access point and is allocated for the terminal, sothat terminals may send ACK responses or BA responses to the accesspoint on corresponding subchannels at the same time, that is, a mannerin which the access point allocates a subchannel for each terminalaccording to OFDMA physical layer signaling enables the access point toperform an indication for more terminals when sending ACK responses orBA responses to the access point, that is, a quantity of terminals towhich the access point indicates subchannels is not limited, andtherefore ACK responses or BA responses of multiple terminals aretransmitted to the access point in parallel, and corresponding timefrequency resources are fully used.

Embodiment 10

FIG. 8 is a schematic flowchart of Embodiment 10 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsOFDMA physical layer signaling carrying an OFDMA ACK request or an OFDMABA request to a terminal, so that the terminal replies with an ACKresponse or a BA response on a subchannel corresponding to the terminalin an OFDMA mode. As shown in FIG. 8, the method includes:

S801: An access point sends OFDMA physical layer signaling to aterminal.

Specifically, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode, that is, theaccess point requests the terminal to reply to the access point with anACK response or a BA response after the terminal obtains correspondingOFDMA+MU-MIMO data information, so as to learn whether the followingOFDMA+MU-MIMO data information is transmitted successfully. The OFDMAphysical layer signaling is used for indicating, to the terminal, thecorresponding subchannel on which the ACK response or the BA response issent to the access point and that is allocated for the terminal.

S802: The access point sends OFDMA+MU-MIMO data information to theterminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode.

Optionally, the OFDMA+MU-MIMO data information may carry the OFDMAphysical layer signaling, or may not carry the OFDMA physical layersignaling.

S803: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding subchannel in an OFDMAmode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or the BA responseis sent to the access point, the terminal sends the ACK response or theBA response to the access point on the corresponding subchannel in theOFDMA or OFDMA+MU-MIMO mode (in this case, the access point not onlyneeds to indicate allocation of the subchannel in the OFDMA physicallayer signaling, but also needs to further indicate a MU-MIMO space-timestream allocation situation in each subchannel). That is, all terminalsmay send ACK responses or BA responses to the access point on respectivecorresponding subchannels at the same time, that is, ACK responses or BAresponses of multiple terminals may be transmitted in parallel, and thencorresponding time frequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling to a terminal, where the OFDMA physical layer signaling isused for indicating, to the terminal, a subchannel that sends an ACKresponse or a BA response to the access point and is allocated for theterminal, so that terminals may send ACK responses or BA responses tothe access point on corresponding sub channels at the same time, thatis, a manner in which the access point allocates a subchannel for eachterminal according to OFDMA physical layer signaling enables the accesspoint to perform an indication for more terminals when sending ACKresponses or BA responses to the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 11

FIG. 9 is a schematic flowchart of Embodiment 11 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsOFDMA physical layer signaling, and an ACK request frame or a BA requestframe to a terminal, so that the terminal replies with an ACK responseor a BA response on a subchannel corresponding to the terminal in anOFDMA mode. As shown in FIG. 9, the method includes:

S901: An access point sends OFDMA physical layer signaling to aterminal.

Specifically, the OFDMA physical layer signaling is used for indicating,to the terminal, the corresponding subchannel on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal.

S902: The access point sends OFDMA+MU-MIMO data information to theterminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode.

Optionally, the OFDMA+MU-MIMO data information may carry the OFDMAphysical layer signaling, or may not carry the OFDMA physical layersignaling.

S903: The access point sends an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode.

Optionally, the ACK request frame or the BA request frame may carry theOFDMA physical layer signaling, or may not carry the OFDMA physicallayer signaling. Moreover, optionally, when the foregoing OFDMA+MU-MIMOdata information carries the OFDMA physical layer signaling, the ACKrequest frame or the BA request frame may not carry the OFDMA physicallayer signaling; or when the foregoing OFDMA+MU-MIMO data informationdoes not carry the OFDMA physical layer signaling, the ACK request frameor the BA request frame may carry the OFDMA physical layer signaling.

S904: The access point receives the ACK response or the BA response thatis sent by the terminal on the corresponding sub channel in an OFDMAmode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal determines according to thededicated information bit in the ACK request frame or the BA requestframe to send the ACK response or BA response to the access point on thecorresponding subchannel in the OFDMA or OFDMA+MU-MIMO mode. That is,all terminals may send ACK responses or BA responses to the access pointon respective corresponding subchannels at the same time, that is, ACKresponses or BA responses of multiple terminals may be transmitted inparallel, and then corresponding time frequency resources can be fullyused.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling to a terminal, where the OFDMA physical layer signaling isused for indicating, to the terminal, a subchannel that sends an ACKresponse or a BA response to the access point and is allocated for theterminal, so that terminals may send ACK responses or BA responses tothe access point on corresponding subchannels at the same time, that is,a manner in which the access point allocates a subchannel for eachterminal according to OFDMA physical layer signaling enables the accesspoint to perform an indication for more terminals when sending ACKresponses or BA responses to the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 12

FIG. 10 is a schematic flowchart of Embodiment 12 of a data transmissionindication method according to the present invention. The method of thisembodiment involves a process of transmission of uplink OFDMA datainformation initiated by a terminal. The method specifically includesthe following steps:

S1001: An access point receives an uplink transmission frame sent by aterminal.

Specifically, the method involved in this embodiment is the foregoingprocess of transmission of uplink OFDMA data information initiated by aSTA, and the uplink transmission frame carries an OFDMA datatransmission request.

The terminal may transmit an uplink transmission frame in an OFDM mode,where the uplink transmission frame may be specifically of any type. Theterminal may add an OFDMA data transmission request to the uplinktransmission frame, where the OFDMA data transmission request is usedfor requesting the access point to complete subsequent data transmissionin an OFDMA mode.

After receiving the uplink transmission frame of the terminal, theaccess point decides according to the OFDMA data transmission request ofthe terminal or a current network situation whether to switch theterminal to the OFDMA mode to perform transmission, for example, whetherthere is a requirement from another terminal at the access point. If theaccess point determines that the terminal needs to be switched to theOFDMA mode, the access point uses the OFDMA mode in subsequent datatransmission; or if a determining result of the access point is that theterminal is not switched to the OFDMA mode, the access point continuesto perform data transmission in the OFDM mode.

S1002: The access point sends OFDMA physical layer signaling to theterminal.

Specifically, when the access point determines according to the OFDMAdata transmission request or the current network situation that theterminal needs to be switched to the OFDMA mode, and performs datatransmission in the OFDMA mode, the access point sends the OFDMAphysical layer signaling to the terminal, where the OFDMA physical layersignaling is used for instructing terminals to send the uplink OFDMAdata information on respective corresponding subchannels.

It should be noted that, the OFDMA physical layer signaling may becarried in the OFDM preamble in the foregoing embodiment, or may becarried in the NDPA frame, or the NDPA frame and the OFDM preamble maycooperate with each other to carry the OFDMA physical layer signaling.For a specific process, reference may be made to the foregoingembodiment, and details are not described herein again. Optionally, anexample in which the OFDMA physical layer signaling is carried in theOFDM preamble is used (referring to an example in FIG. 10a ), the OFDMpreamble part may be transmitted only on the primary channel, or may betransmitted on multiple subchannels (including the primary channel), andreference is made to an example in FIG. 10 b.

Optionally, after S1002, the access point may further send downlinkOFDMA data information of the terminals on the respective subchannelscorresponding to the foregoing terminals. For a downlink OFDMA datatransmission process, reference may be made to the foregoing embodiment,and details are not described herein again.

The terminal learns, by using the subchannel indicated by the OFDMAphysical layer signaling, the subchannel on which the terminal sends theuplink OFDMA data information to the access point, that is, signalingindication occurring when the access point additionally instructs theterminal to transmit the uplink OFDMA data information is avoided, andsystem efficiency is improved.

S1003: The access point receives uplink OFDMA data information that issent by the terminal on a corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, a subchannel on which the uplink OFDMA data information issent to the access point, the terminal sends the uplink OFDMA datainformation to the access point on the subchannel.

Optionally, if after S1002, the access point further sends downlinkOFDMA data information to the terminal, after the terminal receives, ona corresponding subchannel, the downlink OFDMA data information sent bythe access point and waits for a fixed time length, the terminal sendsthe uplink OFDMA data information associated with the terminal on thesubchannel.

In the data transmission indication method provided in this embodimentof the present invention, a terminal sends an uplink transmission frameto an access point, so that the access point indicates, for eachterminal by using OFDMA physical layer signaling, a subchannel on whichuplink OFDMA data information is sent, and therefore each terminal maysend data to the access point on the corresponding subchannel. That is,a subchannel is allocated for a terminal in a manner in which the accesspoint sends the OFDMA physical layer signaling, so that the access pointmay perform an indication for more terminals when the uplink OFDMA datainformation is sent to the access point, signaling indication occurringwhen the access point additionally instructs the terminal to transmitthe uplink OFDMA data information is avoided, and system efficiency isimproved.

Further, the method involved in this embodiment is directed to a processin which in the foregoing scenario shown in FIG. 10 that a terminalsends uplink OFDMA data information to an access point, after receivingthe uplink OFDMA data information sent by the terminal, the access pointsends an ACK response or a BA response to the terminal on acorresponding subchannel. Further, after S1003, the method furtherincludes:

S1004: The access point sends an ACK response or a BA responsecorresponding to the uplink OFDMA data information on the subchannelcorresponding to the terminal in the OFDMA mode.

Specifically, the terminal sends the uplink OFDMA data information tothe access point on the subchannel corresponding to the terminal, wherethe uplink OFDMA data information carries an OFDMA ACK request or anOFDMA BA request, and the OFDMA ACK request or the OFDMA BA request isused for instructing the access point to send an ACK response or a BAresponse to the terminal in the OFDMA mode, that is, making the accesspoint feed back a transmission situation of the uplink OFDMA datainformation to the terminal.

The access point is a subject sending the OFDMA physical layersignaling, and therefore, the access point may directly send the ACKresponse or the BA response of the uplink OFDMA data informationassociated with the terminal on the corresponding subchannel to theterminal, so that terminal learns whether the uplink OFDMA data istransmitted successfully.

It should be noted that, the frame format and the indication manner inEmbodiment 1 to Embodiment 3 are also applicable to a case in which theaccess point replies terminals with the ACK or BA response in parallelin the OFDMA mode for uplink multi-user transmission data (the uplinkOFDMA data information or uplink MU-MIMO data information).

In the data transmission indication method provided in this embodimentof the present invention, an ACK request or a BA request is carried inuplink OFDMA data information sent by a terminal to an access point, sothat the access point can send an ACK response or a BA responsecorresponding to the uplink OFDMA data information to the terminal on acorresponding subchannel. That is, a manner in which the access pointallocates a subchannel for each terminal according to OFDMA physicallayer signaling enables the access point to perform an indication formore terminals when sending uplink OFDMA data to the access point, thatis, a quantity of terminals to which the access point indicatessubchannels is not limited, and therefore the terminal can learnaccording to the ACK response or the BA response sent by the accesspoint, whether the uplink OFDMA data is transmitted successfully.

Embodiment 13

FIG. 11 is a schematic flowchart of Embodiment 13 of a data transmissionindication method according to the present invention. The method of thisembodiment involves a process of transmission of uplink OFDMA datainformation initiated by an access point. The method specificallyincludes the following steps:

S1101: An access point sends OFDMA physical layer signaling to aterminal.

Specifically, the OFDMA physical layer signaling may be carried in theOFDM preamble in the foregoing embodiment, or may be carried in the NDPAframe, or the NDPA frame and the OFDM preamble may cooperate with eachother to carry the OFDMA physical layer signaling. For a specificprocess, reference may be made to the foregoing embodiment, and detailsare not described herein again.

The OFDMA physical layer signaling is specifically used for indicating,to the terminal, the subchannel that corresponds to the terminal, onwhich uplink OFDMA data information is sent to the access point and thatis allocated for the terminal. Optionally, in all embodiments of thepresent invention, the OFDMA physical layer signaling may include aninformation bit, used for indicating, to the terminal, whether theallocation of the subchannel is used for an uplink, or only used for adownlink, or used for both an uplink and a downlink. In this embodiment,the information bit in the OFDMA physical layer signaling indicates, tothe terminal, that the subchannel is a subchannel used for uplinktransmission. In a case in which the access point obtains a channel useright, the terminal is instructed by using the delivered OFDMA physicallayer signaling to send the uplink OFDMA data information to the accesspoint on the corresponding subchannel. An example in which the OFDMAphysical layer signaling is carried in the OFDM preamble is used, theOFDM part may be transmitted on multiple subchannels (refer to 11 a), ormay be only transmitted on a primary channel (refer to 11 b).

S1102: The access point receives uplink OFDMA data information that issent by the terminal on a corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, a subchannel on which the uplink OFDMA data information issent to the access point, the terminal sends the uplink OFDMA datainformation to the access point on the subchannel; therefore the accesspoint may receive multiple pieces of uplink OFDMA data information thatare sent by terminals on corresponding subchannels, and correspondingtime frequency resources are fully used.

In the data transmission indication method provided in this embodimentof the present invention, an access point indicates, for a terminal byusing OFDMA physical layer signaling, a subchannel on which uplink OFDMAdata information is sent, so that each terminals may send uplink data tothe access point on a corresponding subchannels, and corresponding timefrequency resources are fully used. Moreover, a subchannel is allocatedfor each terminal in a manner in which the access point sends the OFDMAphysical layer signaling, so that the access point may perform anindication for more terminals when sending uplink OFDMA data to theaccess point, that is, a quantity of terminals to which the access pointindicates subchannels is not limited.

Embodiment 14

FIG. 12 is a schematic flowchart of Embodiment 14 of a data transmissionindication method according to the present invention. As shown in FIG.12, the method includes:

S1201: A terminal receives OFDMA physical layer signaling sent by anaccess point, where the OFDMA physical layer signaling is used forindicating, to the terminal, a subchannel allocated by the access pointfor the terminal, where the OFDMA physical layer signaling includes anidentifier of the terminal and subchannel information corresponding tothe identifier of the terminal.

Specifically, the terminal receives the OFDMA physical layer signalingthat is sent by the access point in an OFDM mode, where the OFDM modeherein refers to that the access point may send the OFDMA physical layersignaling to a terminal in a coverage area of the access point, butanother terminal in the coverage area of the access point may alsolisten to obtain and correctly demodulate the OFDMA physical layersignaling. The OFDMA physical layer signaling in this embodiment of thepresent invention includes an identifier of the terminal and subchannelinformation corresponding to the identifier of the terminal.

A channel bandwidth of a subchannel is not limited in the presentinvention, and the access point determines the bandwidth of thesubchannel according to a bandwidth requirement of a terminal. Moreover,the indicated subchannel may be presented in multiple forms, which maybe a center frequency and a bandwidth of the subchannel, or may be achannel number and a bandwidth of a start frequency band, or may be achannel number range from a start frequency band to an end frequencyband, which is not limited in the present invention.

S1202: The terminal determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

Specifically, each terminal may determine a subchannel corresponding tothe terminal according to content included in the OFDMA physical layersignaling, and perform a corresponding operation on the correspondingsubchannel, for example, may receive, on a subchannel corresponding tothe terminal, data that belongs to the terminal and is sent by theaccess point, or may send corresponding response information or uplinkdata information to the access point on a subchannel corresponding tothe terminal. The identifier of the terminal in the foregoing OFDMAphysical layer signaling may be an identifier of a single terminal, ormay be identifiers of a terminal group, and the terminal group mayinclude multiple terminals.

A subchannel indicated by the OFDMA physical layer signaling involved inthis embodiment for a terminal may correspond to one terminal, or maycorrespond to multiple terminals. For example, multiple terminals may begrouped into one group, and the OFDMA physical layer signaling allocatesa subchannel for this group, and then all the terminals in the group mayuse the subchannel.

A format of a signaling part in the prior art can only support abandwidth of 20 MHz, and a user is allocated for each subcarrier for 48subcarriers; when a bandwidth greater than 20 MHz is used, the prior arthas no corresponding expansion solution to support the bandwidth.However, the OFDMA physical layer signaling in this embodiment of thepresent invention may support a larger bandwidth, and for a quantity ofterminals, allocate and indicate an allocated subchannel for multipleterminals, where the subchannel includes one or more subcarriers.Therefore, subjects for this embodiment of the present invention and theprior art are different (in the prior art, the subject is to allocateuser for a subcarrier, and in this embodiment of the present invention,the subject is to allocate a subchannel or a subcarrier for a user), theprior art can only perform indication for 48 terminals because of alimitation of subcarriers, and indicating, by OFDMA physical layersignaling, a subchannel for a terminal may be not limited by abandwidth, subchannels may be allocated for more terminals (users whosequantity exceeds 48) in a larger bandwidth. Certainly, this embodimentof the present invention may still allocate subchannels for terminalswhose quantity is less than 48.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives OFDMA physical layersignaling sent by an access point, and determines a subchannelcorresponding to the terminal, thereby performing a correspondingoperation on the corresponding subchannel. That is, a manner in whichthe access point allocates a subchannel for each terminal according toOFDMA physical layer signaling enables the access point to indicatesubchannels for more terminals, that is, a quantity of terminals towhich the access point indicates subchannels is not limited.

Embodiment 15

FIG. 13 is a schematic flowchart of Embodiment 15 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a feasible implementation manner in whicha subchannel is indicated to a terminal by using OFDMA physical layersignaling. Further, on the basis of the embodiment shown in FIG. 12, theidentifier of the terminal may be an identifier of one or more terminalgroups, each terminal group includes at least one terminal, and thesubchannel information includes an uplink subchannel or a downlinksubchannel or an uplink and downlink bidirectional subchannel. Themethod includes:

S1301: A terminal receives a mapping relationship between an identifierof a terminal group and an address of the terminal, where the mappingrelationship is sent by the access point.

Specifically, the terminal needs to know a terminal group to which theterminal belongs, and then can know a subchannel corresponding to theterminal only when the access point allocates subchannels for theterminal group. Therefore, the access point needs to send a mappingrelationship between an identifier of a terminal group and an address ofa terminal to each terminal, so that each terminal learns a terminalgroup in which the terminal is located. For a simple manner in which aterminal is informed of a mapping relationship between an identifier ofa terminal group and an address of each terminal in a groupingmanagement frame form, reference may be made to the format and therelated description of Table 1, and details are not described hereinagain in this embodiment of the present invention.

S1302: The terminal receives OFDMA physical layer signaling sent by theaccess point, where the OFDMA physical layer signaling includes anidentifier of the terminal and subchannel information corresponding tothe identifier of the terminal, and the OFDMA physical layer signalingis used for indicating to each terminal group that the allocatedsubchannel is an uplink subchannel or a downlink subchannel or an uplinkand downlink bidirectional subchannel.

Optionally, the OFDMA physical layer signaling may indicate by using adedicated indication bit that the subchannel allocated for the terminalis an uplink subchannel or a downlink subchannel or an uplink anddownlink bidirectional subchannel. That is, the foregoing OFDMA physicallayer signaling not only may indicate an allocated subchannel for theterminal group, but also may indicate, to the terminal group, that anallocated subchannel is an uplink subchannel or a downlink subchannel oran uplink and downlink bidirectional subchannel.

Specifically, the identifier of the terminal is an identifier of one ormore terminal groups, and the OFDMA physical layer signaling is used forindicating, to one or more terminal groups, a subchannel allocated foreach terminal group, where terminal groups and subchannels are in aone-to-one correspondence.

For the related field included in the indication of the OFDMA physicallayer signaling, reference may be made to the formats and the relateddescription shown in Table 2 and Table 3, and details are not describedherein again in this embodiment of the present invention.

S1303: The terminal determines, according to the mapping relationshipthat the terminal is located in the terminal group, and then theterminal determines that a subchannel corresponding to the terminalgroup is the subchannel corresponding to the terminal.

In the data transmission indication method provided in this embodimentof the present invention, an access point sends OFDMA physical layersignaling carrying and including an identifier of a terminal andsubchannel information corresponding to the identifier of the terminalto the terminal, and the access point further sends a mappingrelationship between an identifier of a terminal group and an address ofeach terminal to each terminal, so that each terminal learns a terminalgroup in which the terminal is located, and further learns a subchannelcorresponding to the terminal, thereby performing a correspondingoperation on the subchannel. That is, a manner in which the access pointallocates a subchannel for each terminal according to the foregoingOFDMA physical layer signaling enables the access point to indicatesubchannels for more terminals, that is, a quantity of terminals towhich the access point indicates subchannels is not limited.

Embodiment 16

Embodiment 16 of the present invention provides a data transmissionindication method. The method involved in this embodiment is anotherfeasible implementation manner in which an access point indicates asubchannel for a terminal by using OFDMA physical layer signaling. Onthe basis of the embodiment shown in FIG. 12, the OFDMA physical layersignaling may include an identifier of a terminal and subchannelinformation corresponding to the identifier of the terminal; and theidentifier of the terminal is an identifier of a single terminal group,and the terminal group includes at least two terminals; and the OFDMAphysical layer signaling is used for indicating to each terminal in theterminal group that the allocated subchannel is an uplink subchannel ora downlink subchannel or an uplink and downlink bidirectionalsubchannel.

Optionally, the OFDMA physical layer signaling may indicate by using adedicated indication bit that the subchannel allocated for the terminalis an uplink subchannel or a downlink subchannel or an uplink anddownlink bidirectional subchannel. The terminals in the terminal groupand the subchannels are in a one-to-one correspondence. That is, theforegoing OFDMA physical layer signaling not only may indicate anallocated subchannel for each terminal in the terminal group, but alsomay indicate, to each terminal in the terminal group, that an allocatedsubchannel is an uplink subchannel or a downlink subchannel or an uplinkand downlink bidirectional subchannel.

Specifically, for the related field included in the indication of theOFDMA physical layer signaling, reference may be made to the format andthe related description shown in Table 4, and details are not describedherein again in this embodiment of the present invention.

Each terminal in the foregoing terminal group in Table 4 corresponds toa different subchannel, and because the OFDMA physical layer signalingmay support a larger bandwidth (not limited to a bandwidth of 20 MHz),subchannels may be indicated to more terminals.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives OFDMA physical layersignaling sent by an access point, and learns a subchannel to which theterminal corresponds according to the OFDMA physical layer signaling, sothat the terminal may perform a corresponding operation on thesubchannel corresponding to the terminal. That is, a manner in which theaccess point allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to indicatesubchannels for more terminals, that is, a quantity of terminals towhich the access point indicates subchannels is not limited.

Embodiment 17

FIG. 14 is a schematic flowchart of Embodiment 17 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which a terminal receivesOFDMA physical layer signaling carried in an OFDM preamble, learns asubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, and receives, on the subchannel corresponding to theterminal, downlink OFDMA data information sent by an access point. Themethod includes:

S1401: A terminal receives an OFDM preamble sent by an access point,where the OFDM preamble carries OFDMA physical layer signaling.

S1402: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

Specifically, the terminal receives the OFDM preamble that is sent bythe access point in an OFDM mode, where the OFDM mode herein refers tothat the access point sends an OFDM preamble to any terminal in acoverage area of the access point. The OFDM preamble includes an STF, anLTF, L-SIG, and UHT-SIG-A, where the UHT-SIG-A carries OFDMA physicallayer signaling. It should be noted that, that the access point sendsthe OFDM preamble in the OFDM mode refers to that the access point sendsan OFDM preamble to a terminal, but in this case, the access point doesnot know the specific terminal to which the OFDM preamble is sent;therefore the access point sends the OFDM preamble to any terminal, andall active terminals listen to and receive the OFDM preamble, and thenobtain OFDMA physical layer signaling, thereby learning channelscorresponding to the terminals.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1403: The terminal receives, on the corresponding subchannel, downlinkOFDMA data information sent by the access point, where the downlinkOFDMA data information includes an OFDMA preamble and OFDMA data, andthe OFDMA preamble includes a switching field and UHT-SIG-B.

Specifically, the access point sends the downlink OFDMA data informationon the subchannel corresponding to the terminal in the OFDMA mode, thatis, the access point may send the downlink OFDMA data information tomultiple terminals on respective subchannels corresponding to theterminals at the same time, and therefore signaling overheads can bereduced and a multi-user diversity gain can be brought about.Additionally, the subchannel corresponding to the terminal may furtherinclude a primary channel of a BSS, where the primary channel is used bythe access point and the terminal to exchange control signaling andmanagement signaling; that is, after sending the OFDMA physical layersignaling on the primary channel completely, the access point mayrelease the primary channel; or may send the downlink OFDMA datainformation to the terminal by using the primary channel together withanother subchannel.

For a data transmission frame format of the OFDM preamble and thedownlink OFDMA data information, reference may be made to the format andthe related description shown in Table 5, and details are not describedherein again in this embodiment of the present invention.

Additionally, the access point needs to allocate a subchannel for aterminal group, and actually also allocates a subchannel for eachterminal, but data sent by the access point each time is sent for aspecific terminal in the terminal group, and therefore, the terminalneeds to learn an actual terminal address of the terminal in theterminal group. Therefore, the access point further needs to add aspecific destination terminal address to UHT-SIG-B or a media accesscontrol (MAC) layer header transmitted on each subchannel, where thedestination terminal address is an address of an element in a terminalgroup indicated by a group number in Table 1 to Table 4, and theterminal reads the destination terminal address in the UHT-SIG-B or theMAC layer header.

Correspondingly, after determining the received OFDM preamble in theOFDM manner, the terminal reads the OFDMA physical layer signaling ofthe UHT-SIG-A, and determines according to an address of the terminalwhether the terminal is in the terminal group indicated by the OFDMAphysical layer signaling. If the terminal is in the terminal group, theterminal is switched to the OFDMA mode, further switched to theindicated subchannel according to subchannel information correspondingto the terminal group, further receives an OFDMA preamble, anddetermines according to the destination terminal address carried in thereceived UHT-SIG-B or MAC layer header whether the terminal is adestination terminal: if yes, the terminal reads subsequent OFDMA data;or if not, the terminal stops reading. If it is determined that theterminal is not in the terminal group, the terminal may choose to be notswitched to the OFDMA mode, and continue to obtain the OFDMA preambleand the OFDMA data in the OFDM manner.

In the foregoing steps, no matter whether the terminal is a destinationterminal, the terminal may read a time length in the data frame format(that is, includes the OFDM preamble, the OFDMA preamble and the OFDMAdata) to determine a time needed for the transmission. A non-destinationterminal sets a network allocation vector (NAV) of the terminalaccording to the time length. In a time length of the NAV, thenon-destination terminal may choose not to listen to any subchannelagain to reduce power loss of the terminal. Additionally, thenon-destination terminal may also set an NAV according to a length ofL-SIG, and the length herein may indicate a total length of multipledata frames, and is used by the terminal to calculate a time occupied bythe total length.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives an OFDM preamble carryingOFDMA physical layer signaling, and obtains OFDMA physical layersignaling from the OFDM preamble, thereby learning, according to theOFDMA physical layer signaling, a subchannel on which the terminalshould receive downlink OFDMA data information corresponding to theterminal. That is, a manner in which the access point allocates asubchannel for each terminal according to OFDMA physical layer signalingenables the access point to perform an indication for more terminalswhen receiving data of the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited.

Embodiment 18

FIG. 15 is a schematic flowchart of Embodiment 18 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which a terminal obtainsOFDMA physical layer signaling carried in an NDPA frame, learns asubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, and receives, on the subchannel corresponding to theterminal, downlink OFDMA data information sent by an access point. Themethod includes:

S1501: A terminal receives an NDPA frame sent by an access point, wherethe NDPA frame carries OFDMA physical layer signaling.

Specifically, an exclusive NDPA frame is used in this embodiment of thepresent invention to carry OFDMA physical layer signaling, and is usedfor reducing overheads brought about when the OFDMA physical layersignaling is transmitted. For a format of the NDPA frame in thisembodiment of the present invention, reference may be made to Table 6,and details are not described herein again in this embodiment of thepresent invention.

It should be noted that, the access point may send an NDPA frame to aterminal in a coverage area of the access point in an OFDM mode, and maysend the NDPA frame on a primary channel, or may send the NDPA frame onmultiple subchannels, and all other terminals may listen to obtain theNDPA frame. Then, the access point further needs to send an OFDMpreamble in the OFDM mode. The foregoing OFDMA physical layer signalingmay be carried in the NDPA frame, or may be carried in both the NDPAframe and the OFDM preamble, but is generally only carried in the NDPAframe to reduce signaling overheads. Optionally, when the NDPA framecarries the OFDMA physical layer signaling, the OFDM preamble mayfurther indicate a specific terminal identifier in a terminal group.

S1502: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1503: The terminal receives, on the corresponding subchannel, downlinkOFDMA data information sent by the access point, where the downlinkOFDMA data information includes an OFDMA preamble and OFDMA data, andthe OFDMA preamble includes a switching field and UHT-SIG-B.

Specifically, the access point sends the downlink OFDMA data informationin the OFDMA mode, that is, the access point may send the downlink OFDMAdata information to multiple terminals on respective subchannelscorresponding to terminals at the same time, and therefore correspondingtime frequency resources may be fully used. Additionally, the subchannelcorresponding to the terminal may further include a primary channel of aBSS, where the primary channel is used by the access point and theterminal to exchange control signaling and management signaling; thatis, after sending the OFDMA physical layer signaling on the primarychannel completely, the access point may release the primary channel, ormay send the downlink OFDMA data information to the terminal by usingthe primary channel together with another subchannel.

The terminal detects and receives the NDPA frame in the OFDM manner inan idle state, and reads the OFDMA physical layer signaling in the OFDMmanner; and then the terminal also receives the OFDM preamble in theOFDM manner. For a data transmission frame format of the OFDM preambleand the downlink OFDMA data information, reference may be made to theformat and the related description shown in Table 5, and details are notdescribed herein again in this embodiment of the present invention.

Additionally, the access point needs to allocate a subchannel for aterminal group, and actually also allocates a subchannel for eachterminal, but data sent by the access point each time is sent for aspecific terminal in the terminal group, and therefore, the terminalneeds to learn an actual terminal address of the terminal in theterminal group. Therefore, the access point further needs to add aspecific destination terminal address to UHT-SIG-B or a MAC layer headertransmitted on each subchannel, where the destination terminal addressis an address of an element in a terminal group indicated by a groupnumber in Table 1 to Table 4, and the terminal reads the destinationterminal address in the UHT-SIG-B or the MAC layer header.

Correspondingly, after determining the received OFDM preamble in theOFDM manner, the terminal determines according to an address of theterminal whether the terminal is in the terminal group indicated by theOFDMA physical layer signaling. If the terminal is in the terminalgroup, the terminal is switched to the OFDMA mode, further switched tothe indicated subchannel according to subchannel informationcorresponding to the terminal group, further receives an OFDMA preamble,and determines according to the destination terminal address carried inthe received UHT-SIG-B or MAC layer header whether the terminal is adestination terminal: if yes, the terminal reads subsequent OFDMA data;or if not, the terminal stops reading. If it is determined that theterminal is not in the terminal group, the terminal may choose to be notswitched to the OFDMA mode, and continue to obtain the OFDMA preambleand the OFDMA data in the OFDM manner.

In the foregoing steps, no matter whether the terminal is a destinationterminal, the terminal may read a time length in the data frame format(that is, includes the OFDM preamble, the OFDMA preamble and the OFDMAdata) to determine a time needed for the transmission. A non-destinationterminal sets an NAV of the terminal according to the time length. In atime length of the NAV, the non-destination terminal may choose not tolisten to any subchannel again to reduce power loss of the terminal.Additionally, the non-destination terminal may also set an NAV accordingto a length of L-SIG, and the length herein may indicate a total lengthof multiple data frames, and is used by the terminal to calculate a timeoccupied by the total length.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives an NDPA frame carryingOFDMA physical layer signaling and sent by an access point, so that theterminal may obtain OFDMA physical layer signaling from the NDPA frame,thereby learning, according to the OFDMA physical layer signaling, asubchannel on which the terminal should receive downlink OFDMA datainformation corresponding to the terminal, so as to receive, on thecorresponding subchannel, the downlink OFDMA data information sent bythe access point. That is, a manner in which the access point allocatesa subchannel for each terminal according to OFDMA physical layersignaling enables the access point to perform an indication for moreterminals when receiving data of the access point, that is, a quantityof terminals to which the access point indicates subchannels is notlimited.

Embodiment 19

FIG. 16 is a schematic flowchart of Embodiment 19 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsan NDPA frame and an OFDM preamble separately carrying content includedin OFDMA physical layer signaling to a terminal, so that the terminalobtains the OFDMA physical layer signaling from the NDPA frame and theOFDM preamble, and therefore the terminal learns a subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, and receives, on the subchannel corresponding to theterminal, downlink OFDMA data information sent by an access point. Themethod includes:

S1601: A terminal receives an NDPA frame and an OFDM preamble that aresent by an access point.

Specifically, the NDPA frame and the OFDM preamble may carry the OFDMAphysical layer signaling in two cooperative manners, which areseparately:

First manner: A terminal receives an NDPA frame and an OFDM preamblethat are sent by an access point, where the NDPA frame carries anidentifier of the terminal in the foregoing OFDMA physical layersignaling, and the OFDM preamble carries subchannel informationcorresponding to the identifier of the terminal and being in theforegoing OFDMA physical layer signaling. The identifier of the terminalherein may be an identifier of one or more terminal groups in Embodiment2, and subchannels and terminal groups are in a one-to-onecorrespondence; and may be further an identifier of a single terminalgroup in Embodiment 3, and subchannels and terminals in the group are ina one-to-one correspondence.

Second manner: A terminal receives an NDPA frame and an OFDM preamblethat are sent by an access point, where the NDPA frame carriessubchannel information corresponding to an identifier of the terminaland being in the foregoing OFDMA physical layer signaling, and the OFDMpreamble carries the identifier of the terminal in the foregoing OFDMAphysical layer signaling. The identifier of the terminal herein may bean identifier of one or more terminal groups in Embodiment 2, andsubchannels and terminal groups are in a one-to-one correspondence; andmay be further an identifier of a single terminal group in Embodiment 3,and subchannels and terminals in the group are in a one-to-onecorrespondence.

That is, the NDPA frame and the OFDM preamble may cooperate with eachother to indicate the OFDMA physical layer signaling. A user groupinformation field in Table 5 may include the identifier of the terminal,and may further include the subchannel information corresponding to theidentifier of the terminal. Additionally, a control information field ofTable 5 may further indicate an effective time length of subchannelinformation of a currently indicated terminal or terminal group, so thatthe terminal can determine according to the time length whether theindication of the subchannel information of the terminal or terminalgroup is valid or expired, and if not expired, the terminal may continueto use the current subchannel to receive and send data.

If the NDPA frame only carries the identifier of the terminal, the OFDMpreamble further needs to carry the subchannel information correspondingto the identifier of the terminal and being in the NDPA frame; or if theNDPA frame only carries the subchannel information, the OFDM preamblefurther needs to carry the identifier of the terminal corresponding tothe subchannel information and being in the NDPA frame.

S1602: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1603: The terminal receives, on the corresponding subchannel, downlinkOFDMA data information sent by the access point, where the downlinkOFDMA data information includes an OFDMA preamble and OFDMA data, andthe OFDMA preamble includes a switching field and UHT-SIG-B.

Specifically, the access point sends the downlink OFDMA data informationin the OFDMA mode, that is, the access point may send the downlink OFDMAdata information to multiple terminals on respective subchannelscorresponding to terminals at the same time, and therefore correspondingtime frequency resources may be fully used. Additionally, the subchannelcorresponding to the terminal may further include a primary channel of aBSS, where the primary channel is used by the access point and theterminal to exchange control signaling and management signaling; thatis, after sending the OFDMA physical layer signaling on the primarychannel completely, the access point may release the primary channel, ormay send the downlink OFDMA data information to the terminal by usingthe primary channel together with another subchannel.

The terminal detects and receives the NDPA frame in the OFDM manner inan idle state, and reads a part of the OFDMA physical layer signalingcarried in the NDPA frame; and then the terminal also receives the OFDMpreamble in the OFDM mode, and then reads that part of content that issupplemented for the OFDMA physical layer signaling and in the OFDMpreamble.

For a data transmission frame format of the OFDM preamble and thedownlink OFDMA data information, reference may be made to the format andthe related description shown in Table 5, and details are not describedherein again in this embodiment of the present invention.

Additionally, the access point needs to allocate a subchannel for aterminal group, and actually also allocates a subchannel for eachterminal, but data sent by the access point each time is sent for aspecific terminal in the terminal group, and therefore, the terminalneeds to learn an actual terminal address of the terminal in theterminal group. Therefore, the access point further needs to add aspecific destination terminal address to UHT-SIG-B or a MAC layer headertransmitted on each subchannel, where the destination terminal addressis an address of an element in a terminal group indicated by a groupnumber in Table 1 to Table 4, and the terminal reads the destinationterminal address in the UHT-SIG-B or the MAC layer header.

Correspondingly, after determining the received OFDM preamble in theOFDM mode, the terminal determines according to an address of theterminal whether the terminal is in the terminal group indicated by theOFDMA physical layer signaling. If the terminal is in the terminalgroup, the terminal is switched to the OFDMA mode, further switched tothe indicated subchannel according to subchannel informationcorresponding to the terminal group, further receives an OFDMA preamble,and determines according to the destination terminal address carried inthe received UHT-SIG-B or MAC layer header whether the terminal is adestination terminal: if yes, the terminal reads subsequent OFDMA data;or if not, the terminal stops reading. If it is determined that theterminal is not in the terminal group, the terminal may choose to be notswitched to the OFDMA mode, and continue to obtain the OFDMA preambleand the OFDMA data in the OFDM mode.

In the foregoing steps, no matter whether the terminal is a destinationterminal, the terminal may read a time length in the data frame format(that is, includes the OFDM preamble, the OFDMA preamble and the OFDMAdata) to determine a time needed for the transmission. A non-destinationterminal sets an NAV of the terminal according to the time length. In atime length of the NAV, the non-destination terminal may choose not tolisten to any subchannel again to reduce power loss of the terminal.Additionally, the non-destination terminal may also set an NAV accordingto a length of L-SIG, and the length herein may indicate a total lengthof multiple data frames, and is used by the terminal to calculate a timeoccupied by the total length.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives an NDPA frame and an OFDMpreamble that carry OFDMA physical layer signaling and are sent by anaccess point, and learns, by using the OFDMA physical layer signaling inthe NDPA frame and the OFDM preamble, a subchannel on which the terminalshould receive downlink OFDMA data information corresponding to theterminal, so as to receive the downlink OFDMA data information sent bythe access point. That is, a manner in which the access point allocatesa subchannel for each terminal according to OFDMA physical layersignaling enables the access point to perform an indication for moreterminals when receiving data of the access point, that is, a quantityof terminals to which the access point indicates subchannels is notlimited.

Further, on the basis of the embodiments shown in FIG. 14 to FIG. 16, asa feasible implementation manner of the embodiments of the presentinvention, the method involved in this implementation is a process inwhich after receiving downlink OFDMA data information sent by an accesspoint, a terminal sends an ACK response or a BA response to the accesspoint on a corresponding subchannel. Optionally, the foregoing OFDMAphysical layer signaling or OFDMA data carries an OFDMA ACK request oran OFDMA BA request, and the OFDMA ACK request or the OFDMA BA requestis used for instructing the terminal to send an ACK response or a BAresponse to the access point in an OFDMA mode; and then the foregoingOFDMA physical layer signaling is further used for indicating thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal. That is, after S1403 or S1503 or S1603, an operation ofS20 may be performed:

S30: The terminal sends the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

Specifically, to indicate that the downlink OFDMA data information sentby the access point is correctly received by each terminal, eachterminal needs to reply to the access point with an ACK response or a BAresponse. If the access point adds the OFDMA ACK request or OFDMA BArequest to the downlink OFDMA data information or OFDMA physical layersignaling, after receiving the downlink OFDMA data information on thesubchannel corresponding to the terminal according to the indication ofthe OFDMA physical layer signaling of the access point, the terminal maydirectly reply with an ACK or BA response in the OFDMA mode on thesubchannel indicated by the OFDMA physical layer signaling. The ACKresponse corresponds to the OFDMA ACK request, and the BA responsecorresponds to the OFDMA BA request. Then, the access point receives ACKresponses or BA responses that are sent by terminals on respectivecorresponding subchannels. That is, multiple terminals are enabled tosend responses to the access point on subchannels corresponding to theterminals at the same time, and corresponding time frequency resourcesare fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives, on a subchannel indicatedby OFDMA physical layer signaling, downlink OFDMA data information sentby an access point, and multiple terminals may send ACK responses or BAresponses to the access point at the same time on correspondingsubchannels, that is, a manner in which the access point allocates asubchannel for each terminal according to OFDMA physical layer signalingenables the access point to perform an indication for more terminalswhen sending ACK responses or BA responses to the access point, that is,a quantity of terminals to which the access point indicates subchannelsis not limited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Further, on the basis of the embodiments shown in FIG. 14 to FIG. 16, asanother feasible implementation manner of the embodiments of the presentinvention, the method involved in this embodiment is a process in whichafter receiving OFDMA physical layer signaling and downlink OFDMA datainformation that are sent by an access point, a terminal receives asingle ACK request frame or BA request frame sent by the access point,so that the terminal can send an ACK response or a BA response to theaccess point on a subchannel indicated by the OFDMA physical layersignaling. The foregoing OFDMA physical layer signaling may be furtherused for indicating the subchannel that corresponds to the terminal, onwhich the ACK response or the BA response is sent to the access pointand that is allocated for the terminal. After S202 or S302 or S402, thefollowing steps may be performed:

S40: The terminal receives an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode.

Specifically, after sending the downlink OFDMA data information to theterminal, the access point may further send a single ACK request frameor BA request frame to the terminal (referring to FIG. 4b , an examplein which a BA request frame is individually sent is used), where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode. Optionally, the ACK request frame or the BA requestframe may carry the OFDMA physical layer signaling, or may not carry theOFDMA physical layer signaling. The terminal determines, according tothe OFDMA physical layer signaling, a subchannel on which the terminalsends the ACK response or the BA response to the access point.

Representation of the dedicated information bit may be to identify theACK request frame or the BA request frame as a frame type used forinstructing the terminal to send an ACK response or a BA response to theaccess point in the OFDMA mode (that is, a new frame type different froma conventional ACK request frame or BA request frame). Representation ofanother dedicated information bit may also be: in a case in which aframe type of the ACK request frame or BA request frame is not changed,the dedicated information bit is directly used for instructing theterminal to send an ACK response or a BA response to the access point inthe OFDMA mode.

Additionally, similar to the OFDM preamble, the ACK request frame or BArequest frame may be sent only on the primary channel, or may be sent onall subchannels in a duplicated transmission manner.

S21: The terminal sends the ACK response or the BA response to theaccess point on the corresponding subchannel in the OFDMA mode.

Specifically, after learning, according to the OFDMA physical layersignaling, the subchannel on which the terminal sends the ACK responseor BA response to the access point, the terminal sends the ACK responseor BA response to the access point on the corresponding subchannel inthe OFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and corresponding timefrequency resources are fully used.

Optionally, if the subchannel of the terminal is multiple unit channels(such as, channels whose unit is 20 MHz), the terminal may send an ACKresponses or a BA responses on these multiple unit channels in theduplicated transmission manner, or may send an ACK responses or a BAresponses in a non-duplicated transmission manner.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives OFDMA physical layersignaling sent by an access point, and determines, according to the OFDMphysical layer signaling, a subchannel on which an ACK response or a BAresponse is sent to the access point. That is, a manner in which theaccess point allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to perform anindication for more terminals when sending ACK responses or BA responsesto the access point, that is, a quantity of terminals to which theaccess point indicates subchannels is not limited, and therefore ACKresponses or BA responses of multiple terminals are transmitted to theaccess point in parallel, and corresponding time frequency resources arefully used.

Embodiment 20

FIG. 17 is a schematic flowchart of Embodiment 20 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsMU-MIMO data information carrying OFDMA physical layer signaling to aterminal, and adds an OFDMA ACK request or an OFDMA BA request to theOFDMA physical layer signaling, so that the terminal replies with an ACKresponse or a BA response on a subchannel corresponding to the terminalin an OFDMA mode. As shown in FIG. 17, the method includes:

S1701: A terminal receives MU-MIMO data information sent by an accesspoint, where the MU-MIMO data information carries OFDMA physical layersignaling.

Specifically, the OFDMA physical layer signaling carried in theforegoing MU-MIMO data information further includes an OFDMA ACK requestor OFDMA BA request, used for instructing the terminal to send an ACKresponse or a BA response to the access point in the OFDMA mode, thatis, the access point requests the terminal to reply with an ACK responseor a BA response after the terminal obtains the corresponding MU-MIMOdata information. The OFDMA physical layer signaling is used forindicating, to the terminal, the subchannel on which the ACK response orthe BA response is sent to the access point and that is allocated forthe terminal.

S1702: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1703: The terminal sends an ACK response or a BA response to the accesspoint on the corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives MU-MIMO data informationcarrying OFDMA physical layer signaling and sent by an access point, anddetermines, according to the OFDMA physical layer signaling, asubchannel on which the terminal sends an ACK response or a BA responseto the access point, so that terminals may send ACK responses or BAresponses to the access point on corresponding subchannels at the sametime, that is, a manner in which the access point allocates a subchannelfor each terminal according to OFDMA physical layer signaling enablesthe access point to perform an indication for more terminals whensending ACK responses or BA responses to the access point, that is, aquantity of terminals to which the access point indicates subchannels isnot limited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 21

FIG. 18 is a schematic flowchart of Embodiment 21 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsMU-MIMO data information carrying OFDMA physical layer signaling, and anACK request frame or a BA request frame to a terminal, so that theterminal replies with an ACK response or a BA response on a subchannelcorresponding to the terminal in an OFDMA mode. As shown in FIG. 18, themethod includes:

S1801: A terminal receives MU-MIMO data information sent by an accesspoint, where the MU-MIMO data information carries OFDMA physical layersignaling.

Specifically, the OFDMA physical layer signaling is used for indicating,to the terminal, the subchannel on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal.

S1802: The terminal receives an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode.

Specifically, the terminal receives the ACK request frame or the BArequest frame sent by the access point, that is, the access pointrequests the terminal to reply to the access point with an ACK responseor a BA response to the terminal in the OFDMA mode after the terminalobtains corresponding MU-MIMO data information, so as to learn whetherthe MU-MIMO data information is transmitted successfully.

S1803: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1804: The terminal sends an ACK response or a BA response to the accesspoint on the corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives MU-MIMO data informationcarrying OFDMA physical layer signaling and sent by an access point, anddetermines, according to the OFDMA physical layer signaling, asubchannel on which an ACK response or a BA response is sent to theaccess point, so that terminals may send ACK responses or BA responsesto the access point on corresponding subchannels at the same time, thatis, a manner in which the access point allocates a subchannel for eachterminal according to OFDMA physical layer signaling enables the accesspoint to perform an indication for more terminals when sending ACKresponses or BA responses to the access point, that is, a quantity ofterminals to which the access point indicates subchannels is notlimited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 22

FIG. 19 is a schematic flowchart of Embodiment 22 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsan ACK request frame or a BA request frame carrying OFDMA physical layersignaling to a terminal, so that the terminal replies with an ACKresponse or a BA response on a subchannel corresponding to the terminalin an OFDMA mode. As shown in FIG. 19, the method includes:

S1901: A terminal receives MU-MIMO data information sent by an accesspoint.

S1902: The terminal receives an ACK request frame or a BA request framesent by the access point, where the ACK request frame or the BA requestframe includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; andthe ACK request frame or the BA request frame carries the OFDMA physicallayer signaling.

Specifically, the ACK request frame or the BA request frame sent by theaccess point to the terminal has an objective that lies in that theaccess point requests the terminal to reply to the access point with anACK response or a BA response after the terminal obtains correspondingMU-MIMO data information, so as to learn whether the MU-MIMO datainformation is transmitted successfully. The OFDMA physical layersignaling carried in the ACK request frame or the BA request frame isused for indicating, to the terminal, the subchannel on which the ACKresponse or the BA response is sent to the access point and that isallocated for the terminal.

S1903: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for content included in the OFDMA physicallayer signaling in this embodiment of the present invention, referencemay be made to the description in Embodiment 14 to Embodiment 16, anddetails are not described herein again in this embodiment of the presentinvention.

S1904: The terminal sends the ACK response or the BA response to theaccess point on the subchannel corresponding to the terminal in theOFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in theOFDMA mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives an ACK request frame or aBA request frame carrying OFDMA physical layer signaling and sent by anaccess point, and determines, according to the OFDMA physical layersignaling, a subchannel on which an ACK response or a BA response issent to the access point, so that terminals may send ACK responses or BAresponses to the access point on corresponding subchannels at the sametime, that is, a manner in which the access point allocates a subchannelfor each terminal according to OFDMA physical layer signaling enablesthe access point to perform an indication for more terminals whensending ACK responses or BA responses to the access point, that is, aquantity of terminals to which the access point indicates subchannels isnot limited, and therefore ACK responses or BA responses of multipleterminals are transmitted to the access point in parallel, andcorresponding time frequency resources are fully used.

Embodiment 23

FIG. 20 is a schematic flowchart of Embodiment 23 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsOFDMA physical layer signaling carrying an OFDMA ACK request or an OFDMABA request to a terminal, so that the terminal replies with an ACKresponse or a BA response on a subchannel corresponding to the terminalin an OFDMA mode. As shown in FIG. 20, the method includes:

S2001: A terminal receives OFDMA physical layer signaling sent by anaccess point.

Specifically, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode, that is, theaccess point requests the terminal to reply to the access point with anACK response or a BA response after the terminal obtains correspondingOFDMA+MU-MIMO data information, so as to learn whether the followingOFDMA+MU-MIMO data information is transmitted successfully. The OFDMAphysical layer signaling is used for indicating, to the terminal, thecorresponding subchannel on which the ACK response or the BA response issent to the access point and that is allocated for the terminal.

S2002: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for the OFDMA physical layer signaling in thisembodiment of the present invention, reference may be made to thedescription in Embodiment 14 to Embodiment 16, and details are notdescribed herein again in this embodiment of the present invention.

S2003: The terminal receives, on the corresponding subchannel,OFDMA+MU-MIMO data information sent by the access point.

Optionally, the OFDMA+MU-MIMO data information may carry the OFDMAphysical layer signaling, or may not carry the OFDMA physical layersignaling.

S2004: The terminal sends an ACK response or a BA response to the accesspoint on the corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal sends the ACK response or BAresponse to the access point on the corresponding subchannel in anOFDMA+MU-MIMO mode. That is, all terminals may send ACK responses or BAresponses to the access point on respective corresponding subchannels atthe same time, that is, ACK responses or BA responses of multipleterminals may be transmitted in parallel, and then corresponding timefrequency resources can be fully used.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives OFDMA physical layersignaling sent by an access point, and determines, according to theOFDMA physical layer signaling, a subchannel on which an ACK response ora BA response is sent to the access point, so that terminals may sendACK responses or BA responses to the access point on correspondingsubchannels at the same time, that is, a manner in which the accesspoint allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to perform anindication for more terminals when sending ACK responses or BA responsesto the access point, that is, a quantity of terminals to which theaccess point indicates subchannels is not limited, and therefore ACKresponses or BA responses of multiple terminals are transmitted to theaccess point in parallel, and corresponding time frequency resources arefully used.

Embodiment 24

FIG. 21 is a schematic flowchart of Embodiment 24 of a data transmissionindication method according to the present invention. The methodinvolved in this embodiment is a process in which an access point sendsOFDMA physical layer signaling, and an ACK request frame or a BA requestframe to a terminal, so that the terminal replies with an ACK responseor a BA response on a subchannel corresponding to the terminal in anOFDMA mode. As shown in FIG. 21, the method includes:

S2101: A terminal receives OFDMA physical layer signaling sent by anaccess point.

Specifically, the OFDMA physical layer signaling is used for indicating,to the terminal, the corresponding subchannel on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal.

S2102: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

It should be noted that, for the OFDMA physical layer signaling in thisembodiment of the present invention, reference may be made to thedescription in Embodiment 14 to Embodiment 16, and details are notdescribed herein again in this embodiment of the present invention.

S2103: The terminal receives, on the corresponding subchannel,OFDMA+MU-MIMO data information sent by the access point.

Optionally, the OFDMA+MU-MIMO data information may carry the OFDMAphysical layer signaling, or may not carry the OFDMA physical layersignaling.

S2104: The access point sends an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode.

Specifically, that is, the access point requests, by using an ACKrequest frame or a BA request frame, the terminal to reply to the accesspoint with an ACK response or a BA response after the terminal obtainscorresponding MU-MIMO data information, so as to learn whether thefollowing OFDMA+MU-MIMO data information is transmitted successfully.

Optionally, the ACK request frame or the BA request frame may carry theOFDMA physical layer signaling, or may not carry the OFDMA physicallayer signaling. Moreover, optionally, when the foregoing OFDMA+MU-MIMOdata information carries the OFDMA physical layer signaling, the ACKrequest frame or the BA request frame may not carry the OFDMA physicallayer signaling; or when the foregoing OFDMA+MU-MIMO data informationdoes not carry the OFDMA physical layer signaling, the ACK request frameor the BA request frame may carry the OFDMA physical layer signaling.

S2105: The terminal sends an ACK response or a BA response to the accesspoint on the corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, the subchannel on which the ACK response or BA response issent to the access point, the terminal determines according to thededicated information bit in the ACK request frame or the BA requestframe to send the ACK response or BA response to the access point on thecorresponding subchannel in the OFDMA+MU-MIMO mode. That is, allterminals may send ACK responses or BA responses to the access point onrespective corresponding subchannels at the same time, that is, ACKresponses or BA responses of multiple terminals may be transmitted inparallel, and then corresponding time frequency resources can be fullyused.

In the data transmission indication method provided in this embodimentof the present invention, a terminal receives OFDMA physical layersignaling sent by an access point, and determines, according to theOFDMA physical layer signaling, a subchannel on which an ACK response ora BA response is sent to the access point, so that terminals may sendACK responses or BA responses to the access point on correspondingsubchannels at the same time, that is, a manner in which the accesspoint allocates a subchannel for each terminal according to OFDMAphysical layer signaling enables the access point to perform anindication for more terminals when sending ACK responses or BA responsesto the access point, that is, a quantity of terminals to which theaccess point indicates subchannels is not limited, and therefore ACKresponses or BA responses of multiple terminals are transmitted to theaccess point in parallel, and corresponding time frequency resources arefully used.

Embodiment 25

FIG. 22 is a schematic flowchart of Embodiment 25 of a data transmissionindication method according to the present invention. The method of thisembodiment involves a process of transmission of uplink OFDMA datainformation initiated by a terminal. The method specifically includesthe following steps:

S2201: A terminal sends an uplink transmission frame to an access point.

Specifically, the method involved in this embodiment is the foregoingprocess of transmission of uplink OFDMA data information initiated by aSTA, and the uplink transmission frame carries an OFDMA datatransmission request.

The terminal may transmit an uplink transmission frame in an OFDM mode,where the uplink transmission frame may be specifically of any type. Theterminal may add an OFDMA data transmission request to the uplinktransmission frame, where the OFDMA data transmission request is usedfor requesting the access point to complete subsequent data transmissionin an OFDMA mode.

After receiving the uplink transmission frame of the terminal, theaccess point decides according to the OFDMA data transmission request ofthe terminal or a current network situation whether to switch theterminal to the OFDMA mode to perform transmission, for example, whetherthere is a requirement from another terminal at the access point. If theaccess point determines that the terminal needs to be switched to theOFDMA mode, the access point uses the OFDMA mode in subsequent datatransmission; or if a determining result of the access point is that theterminal is not switched to the OFDMA mode, the access point continuesto perform data transmission in the OFDM mode.

S2202: The terminal receives OFDMA physical layer signaling sent by theaccess point.

Specifically, when the access point determines according to the OFDMAdata transmission request or the current network situation that theterminal needs to be switched to the OFDMA mode, and performs datatransmission in the OFDMA mode, the access point sends the OFDMAphysical layer signaling to the terminal, where the OFDMA physical layersignaling is used for instructing terminals to send the uplink OFDMAdata information on respective corresponding subchannels.

It should be noted that, the OFDMA physical layer signaling may becarried in the OFDM preamble in the foregoing embodiment, or may becarried in the NDPA frame, or the NDPA frame and the OFDM preamble maycooperate with each other to carry the OFDMA physical layer signaling.For a specific process, reference may be made to the foregoingembodiment, and details are not described herein again.

Optionally, after S2202, the access point may further send downlinkOFDMA data information of the terminals on the respective subchannelscorresponding to the foregoing terminals. For a downlink OFDMA datatransmission process, reference may be made to the foregoing embodiment,and details are not described herein again.

S2203: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

Specifically, the terminal learns, by using the subchannel indicated bythe OFDMA physical layer signaling, the subchannel on which the terminalsends the uplink OFDMA data information to the access point, that is,signaling indication occurring when the access point additionallyinstructs the terminal to transmit the uplink OFDMA data information isavoided, and system efficiency is improved.

S2204: The terminal sends uplink OFDMA data information to the accesspoint on the corresponding subchannel in an OFDMA mode.

After determining, according to the OFDMA physical layer signaling, asubchannel on which the uplink OFDMA data information is sent to theaccess point, the terminal sends the uplink OFDMA data information tothe access point on the sub channel.

Optionally, if after S2202, the access point further sends downlinkOFDMA data information to the terminal, after the terminal receives, ona corresponding subchannel, the downlink OFDMA data information sent bythe access point and waits for a fixed time length, the terminal sendsthe uplink OFDMA data information associated with the terminal on thesubchannel.

In the data transmission indication method provided in this embodimentof the present invention, a terminal sends an uplink transmission frameto an access point, so that the access point indicates, for eachterminal by using OFDMA physical layer signaling, a subchannel on whichuplink OFDMA data information is sent, and therefore each terminal maysend data to the access point on the corresponding subchannel. That is,a subchannel is allocated for a terminal in a manner in which the accesspoint sends the OFDMA physical layer signaling, so that the access pointmay perform an indication for more terminals when the uplink OFDMA datainformation is sent to the access point, signaling indication occurringwhen the access point additionally instructs the terminal to transmitthe uplink OFDMA data information is avoided, and system efficiency isimproved.

Further, the method involved in this embodiment is directed to a processin which in the foregoing scenario shown in FIG. 22 that a terminalsends uplink OFDMA data information to an access point, after sendingthe uplink OFDMA data information to the access point, the terminalreceives an ACK response or a BA response that is sent by the accesspoint on a corresponding subchannel. Further, after S2204, the methodfurther includes:

S2205: The terminal receives, on the corresponding subchannel, the ACKresponse or the BA response corresponding to the uplink OFDMA datainformation and sent by the access point.

Specifically, the terminal sends the uplink OFDMA data information tothe access point on the subchannel corresponding to the terminal, wherethe uplink OFDMA data information carries an OFDMA ACK request or anOFDMA BA request, and the OFDMA ACK request or the OFDMA BA request isused for instructing the access point to send an ACK response or a BAresponse to the terminal in the OFDMA mode, that is, making the accesspoint feed back a transmission situation of the uplink OFDMA datainformation to the terminal.

The access point is a subject sending the OFDMA physical layersignaling, and therefore, the access point may directly send the ACKresponse or the BA response of the uplink OFDMA data informationassociated with the terminal on the corresponding subchannel to theterminal, so that terminal learns whether the uplink OFDMA data istransmitted successfully.

In the data transmission indication method provided in this embodimentof the present invention, an ACK request or a BA request is carried inuplink OFDMA data information sent by a terminal to an access point, sothat the access point can send an ACK response or a BA responsecorresponding to the uplink OFDMA data information to the terminal on acorresponding subchannel. That is, a manner in which the access pointallocates a subchannel for each terminal according to OFDMA physicallayer signaling enables the access point to perform an indication formore terminals when sending uplink OFDMA data to the access point, thatis, a quantity of terminals to which the access point indicatessubchannels is not limited, and therefore the terminal can learnaccording to the ACK response or the BA response sent by the accesspoint, whether the uplink OFDMA data is transmitted successfully.

Embodiment 26

FIG. 23 is a schematic flowchart of Embodiment 26 of a data transmissionindication method according to the present invention. The method of thisembodiment involves a process of transmission of uplink OFDMA datainformation initiated by an access point. The method specificallyincludes the following steps:

S2301: A terminal receives OFDMA physical layer signaling sent by anaccess point.

Specifically, the OFDMA physical layer signaling may be carried in theOFDM preamble in the foregoing embodiment, or may be carried in the NDPAframe, or the NDPA frame and the OFDM preamble may cooperate with eachother to carry the OFDMA physical layer signaling. For a specificprocess, reference may be made to the foregoing embodiment, and detailsare not described herein again.

The OFDMA physical layer signaling is specifically used for indicating,to the terminal, the subchannel that corresponds to the terminal, onwhich uplink OFDMA data information is sent to the access point and thatis allocated for the terminal. Optionally, in all embodiments of thepresent invention, the OFDMA physical layer signaling may include aninformation bit, used for indicating, to the terminal, whether theallocation of the subchannel is used for an uplink, or only used for adownlink, or used for both an uplink and a downlink. In this embodiment,the information bit in the OFDMA physical layer signaling indicates, tothe terminal, that the subchannel is a subchannel used for uplinktransmission. In a case in which the access point obtains a channel useright, the terminal is instructed by using the delivered OFDMA physicallayer signaling to send the uplink OFDMA data information to the accesspoint on the corresponding subchannel.

S2302: The terminal determines a subchannel corresponding to theterminal according to the OFDMA physical layer signaling.

Specifically, the terminal learns, by using the subchannel indicated bythe OFDMA physical layer signaling, the subchannel on which the terminalsends the uplink OFDMA data information to the access point, that is,signaling indication occurring when the access point additionallyinstructs the terminal to transmit the uplink OFDMA data information isavoided, and system efficiency is improved.

S2303: The terminal sends uplink OFDMA data information to the accesspoint on the corresponding subchannel in an OFDMA mode.

Specifically, after determining, according to the OFDMA physical layersignaling, a subchannel on which the uplink OFDMA data information issent to the access point, the terminal sends the uplink OFDMA datainformation to the access point on the subchannel.

In the data transmission indication method provided in this embodimentof the present invention, an access point indicates, for a terminal byusing OFDMA physical layer signaling, a subchannel on which uplink OFDMAdata is sent, so that each terminals may send data to the access pointon a corresponding subchannels. That is, a subchannel is allocated foreach terminal in a manner in which the access point sends the OFDMAphysical layer signaling, so that the access point may perform anindication for more terminals when sending uplink OFDMA data to theaccess point, that is, a quantity of terminals to which the access pointindicates subchannels is not limited.

Persons of ordinary skill in the art should understand that, all or partof the steps of the foregoing method embodiments may be implemented by aprogram instructing relevant hardware. The foregoing program may bestored in a computer readable storage medium. When the program is run,the foregoing steps included in the method embodiments are performed.The foregoing storage medium may be any medium capable of storingprogram code, such as a read-only memory (ROM), a random access memory(RAM), a magnetic disk, or an optical disc.

An access point embodiment 1 of the present invention provides an accesspoint, where the access point includes: a sending module 10, configuredto send OFDMA physical layer signaling to a terminal, where the OFDMAphysical layer signaling is used for indicating, to the terminal, asubchannel allocated for the terminal, so that the terminal determinesthe subchannel corresponding to the terminal according to the OFDMAphysical layer signaling, where the OFDMA physical layer signalingincludes an identifier of the terminal and subchannel informationcorresponding to the identifier of the terminal.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Optionally, the identifier of the terminal is an identifier of one ormore terminal groups, and each terminal group includes at least oneterminal; and the subchannel information includes an uplink subchannelor a downlink subchannel or an uplink and downlink bidirectionalsubchannel, and then the OFDMA physical layer signaling being used forindicating, to the terminal, a subchannel allocated for the terminalincludes: the OFDMA physical layer signaling being used for indicatingto each terminal group that the allocated subchannel is an uplinksubchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminal groups and subchannels are in aone-to-one correspondence; and then the sending module 10 is furtherconfigured to: before the OFDMA physical layer signaling is sent to theterminal, send a mapping relationship between an identifier of theterminal group and an address of the terminal to the terminal, so thatthe terminal learns a terminal group in which the terminal is located.

Optionally, the identifier of the terminal is an identifier of oneterminal group, and the terminal group includes at least two terminals;and then the OFDMA physical layer signaling is used for indicating toeach terminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where each terminal in the terminal group andthe subchannel are in a one-to-one correspondence.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Optionally, the sending module 10 is specifically configured to send anOFDM preamble to the terminal, where the OFDM preamble carries the OFDMAphysical layer signaling.

Optionally, the sending module 10 is further configured to send a NDPAframe to the terminal, where the NDPA frame carries the foregoing OFDMAphysical layer signaling.

Optionally, the sending module 10 is further configured to send an NDPAframe and an OFDM preamble to the terminal, where the NDPA frame carriesan identifier of the terminal in the foregoing OFDMA physical layersignaling, and the OFDM preamble carries subchannel informationcorresponding to the identifier of the terminal and being in theforegoing OFDMA physical layer signaling.

Optionally, the sending module 10 is further configured to send an NDPAframe and an OFDM preamble to the terminal, where the NDPA frame carriessubchannel information corresponding to an identifier of the terminaland being in the foregoing OFDMA physical layer signaling, and the OFDMpreamble carries the identifier of the terminal in the foregoing OFDMAphysical layer signaling.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

FIG. 24 is a schematic structural diagram of Embodiment 2 of an accesspoint according to the present invention. Further, on the basis of theforegoing apparatus embodiment 1, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, a subchannel that isallocated to the terminal for receiving downlink OFDMA data information,and then the sending module 10 is further configured to: after the OFDMAphysical layer signaling is sent to the terminal, send downlink OFDMAdata information on the subchannel corresponding to the terminal in anOFDMA mode, where the downlink OFDMA data information includes an OFDMApreamble and OFDMA data, and the OFDMA preamble includes a switchingfield and UHT-SIG-B.

Further, the OFDMA physical layer signaling or the downlink OFDMA datainformation carries an OFDMA ACK request or an OFDMA BA request, and theOFDMA ACK request or the OFDMA BA request is used for instructing theterminal to send an ACK response or a BA response to the access point inthe OFDMA mode; and then the OFDMA physical layer signaling is furtherused for indicating the subchannel that corresponds to the terminal, onwhich the ACK response or the BA response is sent to the access pointand that is allocated for the terminal.

Then, on the basis of the foregoing apparatus embodiment 1, referring toFIG. 24, the access point further includes a receiving module 11,configured to: after the sending module 10 sends the downlink OFDMA datainformation on the subchannel corresponding to the terminal in the OFDMAmode, receive the ACK response or the BA response that is sent by theterminal on the subchannel corresponding to the terminal in the OFDMAmode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is used for indicatingthe subchannel that corresponds to the terminal, on which the ACKresponse or the BA response is sent to the access point and that isallocated for the terminal; and then the sending module 10 is furtherconfigured to: after the downlink OFDMA data information is sent on thesubchannel corresponding to the terminal, send an ACK request frame or aBA request frame to the terminal; and the receiving module 11 is furtherconfigured to receive the ACK response or the BA response that is sentby the terminal on the corresponding subchannel in the OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the sending module 10 isspecifically configured to send MU-MIMO data information to the terminalin a MU-MIMO mode, where the MU-MIMO data information carries the OFDMAphysical layer signaling; and the receiving module 11 is furtherconfigured to: after the sending module 10 sends the OFDMA physicallayer signaling to the terminal, receive the ACK response or the BAresponse that is sent by the terminal on the corresponding subchannel inthe OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thesending module 10 is specifically configured to send MU-MIMO datainformation to the terminal in a MU-MIMO mode, where the MU-MIMO datainformation carries OFDMA physical layer signaling; and send an ACKrequest frame or a BA request frame to the terminal, where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode; and the receiving module 11 is further configured to:after the sending module 10 sends the OFDMA physical layer signaling tothe terminal, receive the ACK response or the BA response that is sentby the terminal on the subchannel corresponding to the terminal in theOFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thesending module 10 is specifically configured to send MU-MIMO datainformation to the terminal in a MU-MIMO mode; and send an ACK requestframe or a BA request frame to the terminal, where the ACK request frameor the BA request frame includes a dedicated information bit, and thededicated information bit is used for instructing the terminal to sendthe ACK response or the BA response to the access point in the OFDMAmode; and the ACK request frame or the BA request frame carries theOFDMA physical layer signaling; and the receiving module 11 is furtherconfigured to: after the sending module 10 sends the OFDMA physicallayer signaling to the terminal, receive the ACK response or the BAresponse that is sent by the terminal on the corresponding subchannel inthe OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the sending module 10 is furtherconfigured to: after the OFDMA physical layer signaling is sent to theterminal, send OFDMA+MU-MIMO data information to the terminal on thesubchannel corresponding to the terminal in an OFDMA+MU-MIMO mode; andthe receiving module 11 is further configured to receive the ACKresponse or the BA response that is sent by the terminal on thecorresponding sub channel in the OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thesending module 10 is further configured to: after the OFDMA physicallayer signaling is sent to the terminal, send OFDMA+MU-MIMO datainformation to the terminal on the subchannel corresponding to theterminal in an OFDMA+MU-MIMO mode; and send an ACK request frame or a BArequest frame to the terminal, where the ACK request frame or the BArequest frame includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; andthe receiving module 11 is further configured to receive the ACKresponse or the BA response that is sent by the terminal on thecorresponding subchannel in the OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the receivingmodule 11 is further configured to: before the sending module 10 sendsthe OFDMA physical layer signaling to the terminal, receive an uplinktransmission frame sent by the terminal; and after the sending module 10sends the OFDMA physical layer signaling to the terminal, receive theuplink OFDMA data information that is sent by the terminal on thecorresponding subchannel in an OFDMA mode.

Further, the uplink OFDMA data information carries an OFDMA ACK requestor an OFDMA BA request, and the OFDMA ACK request or the OFDMA BArequest is further used for instructing the access point to send an ACKresponse or a BA response to the terminal in the OFDMA mode; and thenthe sending module 10 is further configured to: after the receivingmodule 11 receives the uplink OFDMA data information that is sent by theterminal on the corresponding subchannel, send the ACK response or theBA response corresponding to the uplink OFDMA data information on thesubchannel corresponding to the terminal in the OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Referring to FIG. 24 continuously, on the basis of the embodiment shownin FIG. 24, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the receivingmodule 11 is further configured to: after the sending module 10 sendsthe OFDMA physical layer signaling to the terminal, receive the uplinkOFDMA data information that is sent by the terminal on the correspondingsubchannel in an OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

FIG. 25 is a schematic structural diagram of Embodiment 1 of a terminalaccording to the present invention. As shown in FIG. 25, the terminalincludes a receiving module 20 and a determining module 21.

The receiving module 20 is configured to receive OFDMA physical layersignaling sent by an access point, where the OFDMA physical layersignaling is used for indicating, to the terminal, a subchannelallocated by the access point for the terminal, where the OFDMA physicallayer signaling includes an identifier of the terminal and subchannelinformation corresponding to the identifier of the terminal.

The determining module 21 is configured to determine the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Optionally, the identifier of the terminal is an identifier of one ormore terminal groups, and each terminal group includes at least oneterminal; and the subchannel information includes an uplink subchannelor a downlink subchannel or an uplink and downlink bidirectionalsubchannel, and then the OFDMA physical layer signaling being used forindicating, to the terminal, a subchannel allocated for the terminalincludes: the OFDMA physical layer signaling being used for indicatingto each terminal group that the allocated subchannel is an uplinksubchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminal groups and subchannels are in aone-to-one correspondence; and then the receiving module 20 is furtherconfigured to: before the OFDMA physical layer signaling sent by theaccess point is received, receive a mapping relationship between anidentifier of the terminal group and an address of the terminal, wherethe mapping relationship is sent by the access point; and then thedetermining module 21 is specifically configured to determine accordingto the mapping relationship that the terminal is located in the terminalgroup, and then determine that a subchannel corresponding to theterminal group is the subchannel corresponding to the terminal.

Optionally, the identifier of the terminal is an identifier of oneterminal group, and the terminal group includes at least two terminals;and then the OFDMA physical layer signaling being used for indicating,to the terminal, a subchannel allocated for the terminal includes: theOFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminals in the terminal group andsubchannels are in a one-to-one correspondence.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

On the basis of the embodiment shown in FIG. 25, further, the receivingmodule 20 is specifically configured to receive an OFDM preamble sent bythe access point, where the OFDM preamble carries OFDMA physical layersignaling.

Optionally, the receiving module 20 is further configured to receive aNDPA frame sent by the access point, where the NDPA frame carries OFDMAphysical layer signaling.

Optionally, the receiving module 20 is further configured to receive anNDPA frame and an OFDM preamble that are sent by the access point, wherethe NDPA frame carries the identifier of the terminal in the OFDMAphysical layer signaling, and the OFDM preamble carries the subchannelinformation corresponding to the identifier of the terminal and being inthe OFDMA physical layer signaling.

Optionally, the receiving module 20 is further configured to receive anNDPA frame and an OFDM preamble that are sent by the access point, wherethe NDPA frame carries subchannel information corresponding to anidentifier of the terminal and being in the foregoing OFDMA physicallayer signaling, and the OFDM preamble carries the identifier of theterminal in the foregoing OFDMA physical layer signaling.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

FIG. 26 is a schematic structural diagram of Embodiment 2 of a terminalaccording to the present invention. On the basis of the embodiment shownin FIG. 25, further, the OFDMA physical layer signaling is specificallyused for indicating, to the terminal, a subchannel that is allocated bythe access point to the terminal for receiving downlink OFDMA data, andthen the receiving module 20 is further configured to: after thedetermining module 21 determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, receive, onthe subchannel corresponding to the terminal, downlink OFDMA datainformation sent by the access point, where the downlink OFDMA datainformation includes an OFDMA preamble and OFDMA data, and the OFDMApreamble includes a switching field and UHT-SIG-B.

Then, on the basis of the embodiment shown in FIG. 25, further, thereceiving module 20 includes: a receiving unit 201, configured toreceive a destination terminal address corresponding to the OFDMA dataand sent by the access point; and a determining unit 202, configured todetermine whether the terminal matches the destination terminal address;and if yes, instruct the receiving unit 201 to receive, on thesubchannel corresponding to the terminal, the downlink OFDMA datainformation sent by the access point.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

FIG. 27 is a schematic structural diagram of Embodiment 3 of a terminalaccording to the present invention. The foregoing OFDMA physical layersignaling or the foregoing downlink OFDMA data information carries anOFDMA ACK request or an OFDMA BA request, and the OFDMA ACK request orthe OFDMA BA request is used for instructing the terminal to send an ACKresponse or a BA response to the access point in an OFDMA mode; and thenthe foregoing OFDMA physical layer signaling is further used forindicating the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal. Then, on the basis of the embodiment shownin FIG. 26, further, the foregoing terminal further includes: a sendingmodule 22, configured to: after the receiving module 20 receives, on thesubchannel corresponding to the terminal, the downlink OFDMA datainformation sent by the access point, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the foregoing OFDMA physical layersignaling is further used for indicating the subchannel that correspondsto the terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thereceiving module 20 is further configured to: after the downlink OFDMAdata information sent by the access point is received on the subchannelcorresponding to the terminal, receive an ACK request frame or a BArequest frame sent by the access point, where the ACK request frame orthe BA request frame includes a dedicated information bit, and thededicated information bit is used for instructing the terminal to sendthe ACK response or the BA response to the access point in the OFDMAmode; and the sending module 22 is further configured to send the ACKresponse or the BA response to the access point on the subchannelcorresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signalingcarries an OFDMA ACK request or an OFDMA BA request, and the OFDMA ACKrequest or the OFDMA BA request is used for instructing the terminal tosend an ACK response or a BA response to the access point in an OFDMAmode; then the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thereceiving module 20 is specifically configured to receive MU-MIMO datainformation sent by the access point; and the sending module 22 isfurther configured to: after the determining module 21 determines thesubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, send the ACK response or the BA response to the accesspoint on the subchannel corresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, the subchannel thatcorresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then the receiving module 20 is specifically configured toreceive MU-MIMO data information sent by the access point, where theMU-MIMO data information carries the foregoing OFDMA physical layersignaling; and receive an ACK request frame or a BA request frame sentby the access point, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and the sending module22 is further configured to: after the determining module 21 determinesthe subchannel corresponding to the terminal according to the OFDMAphysical layer signaling, send the ACK response or the BA response tothe access point on the subchannel corresponding to the terminal in theOFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, the subchannel thatcorresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then the receiving module 20 is specifically configured toreceive MU-MIMO data information sent by the access point, and receivean ACK request frame or a BA request frame sent by the access point,where the ACK request frame or the BA request frame includes a dedicatedinformation bit, and the dedicated information bit is used forinstructing the terminal to send the ACK response or the BA response tothe access point in the OFDMA mode; and the ACK request frame or the BArequest frame carries the OFDMA physical layer signaling; and thesending module 22 is further configured to: after the determining module21 determines the subchannel corresponding to the terminal according tothe OFDMA physical layer signaling, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signalingcarries an OFDMA ACK request or an OFDMA BA request, and the OFDMA ACKrequest or the OFDMA BA request is used for instructing the terminal tosend an ACK response or a BA response to the access point in an OFDMAmode; then the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thereceiving module 20 is further configured to: after the determiningmodule 21 determines the subchannel corresponding to the terminalaccording to the OFDMA physical layer signaling, receive, on thesubchannel corresponding to the terminal, OFDMA+MU-MIMO data informationsent by the access point; and the sending module 22 is furtherconfigured to send the ACK response or the BA response to the accesspoint on the subchannel corresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, the subchannel thatcorresponds to the terminal, on which the ACK response or the BAresponse is sent to the access point and that is allocated for theterminal; and then the receiving module 20 is further configured to:after the determining module 21 determines the subchannel correspondingto the terminal according to the OFDMA physical layer signaling,receive, on the subchannel corresponding to the terminal, OFDMA+MU-MIMOdata information sent by the access point; and receive an ACK requestframe or a BA request frame sent by the access point, where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode; and the sending module 22 is further configured tosend the ACK response or the BA response to the access point on thesubchannel corresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, a subchannel on whichuplink OFDMA data information is sent to the access point and that isallocated for the terminal; and then the sending module 22 is furtherconfigured to: before the receiving module 20 receives the OFDMAphysical layer signaling sent by the access point, send an uplinktransmission frame to the access point; and further configured to: afterthe determining module 21 determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, send theuplink OFDMA data information to the access point on the subchannelcorresponding to the terminal in the OFDMA mode.

Further, the uplink OFDMA data information carries an OFDMA ACK requestor an OFDMA BA request, and the OFDMA ACK request or the OFDMA BArequest is further used for instructing the access point to send an ACKresponse or a BA response to the terminal in the OFDMA mode; and thenthe receiving module 20 is further configured to: after the sendingmodule 22 sends the uplink OFDMA data information to the access point,receive, on the subchannel corresponding to the terminal, the ACKresponse or the BA response corresponding to the uplink OFDMA datainformation and sent by the access point.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Referring to FIG. 27 continuously, the OFDMA physical layer signaling isspecifically used for indicating, to the terminal, a subchannelcorresponding to the terminal on which uplink OFDMA data information issent to the access point and that is allocated for the terminal; andthen the sending module 22 is further configured to: after thedetermining module 21 determines the subchannel corresponding to theterminal according to the OFDMA physical layer signaling, send theuplink OFDMA data information to the access point on the subchannelcorresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

An access point embodiment 3 of the present invention provides an accesspoint, where the access point includes: a transmitter 30, configured tosend OFDMA physical layer signaling to a terminal, where the OFDMAphysical layer signaling is used for indicating, to the terminal, asubchannel allocated for the terminal, so that the terminal determinesthe subchannel corresponding to the terminal according to the OFDMAphysical layer signaling, where the OFDMA physical layer signalingincludes an identifier of the terminal and subchannel informationcorresponding to the identifier of the terminal.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Optionally, the identifier of the terminal is an identifier of one ormore terminal groups, and each terminal group includes at least oneterminal; and the subchannel information includes an uplink subchannelor a downlink subchannel or an uplink and downlink bidirectionalsubchannel, and then the OFDMA physical layer signaling being used forindicating, to the terminal, a subchannel allocated for the terminalincludes: the OFDMA physical layer signaling being used for indicatingto each terminal group that the allocated subchannel is an uplinksubchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminal groups and subchannels are in aone-to-one correspondence.

The transmitter 30 may be further configured to: before the OFDMAphysical layer signaling is sent to the terminal, send a mappingrelationship between an identifier of the terminal group and an addressof the terminal to the terminal, so that the terminal learns a terminalgroup in which the terminal is located.

Optionally, the identifier of the terminal is an identifier of oneterminal group, and the terminal group includes at least two terminals;and then the OFDMA physical layer signaling being used for indicating,to the terminal, a subchannel allocated for the terminal includes: theOFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminals in the terminal group andsubchannels are in a one-to-one correspondence.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Further, the transmitter 30 is specifically configured to send an OFDMpreamble to the terminal, where the OFDM preamble carries the OFDMAphysical layer signaling.

Optionally, the transmitter 30 may be further configured to send a NDPAframe to the terminal, where the NDPA frame carries the OFDMA physicallayer signaling.

Optionally, the transmitter 30 may be further configured to send an NDPAframe and an OFDM preamble to the terminal, where the NDPA frame carriesthe identifier of the terminal in the OFDMA physical layer signaling,and the OFDM preamble carries the subchannel information correspondingto the identifier of the terminal and being in the OFDMA physical layersignaling.

Optionally, the transmitter 30 may be further configured to send an NDPAframe and an OFDM preamble to the terminal, where the NDPA frame carriesthe subchannel information corresponding to the identifier of theterminal and being in the OFDMA physical layer signaling, and the OFDMpreamble carries the identifier of the terminal in the OFDMA physicallayer signaling.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Further, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, a subchannel that is allocated to theterminal for receiving downlink OFDMA data information, and then thetransmitter 30 may be further configured to: after the OFDMA physicallayer signaling is sent to the terminal, send downlink OFDMA datainformation on the subchannel corresponding to the terminal in an OFDMAmode, where the downlink OFDMA data information includes an OFDMApreamble and OFDMA data, and the OFDMA preamble includes a switchingfield and UHT-SIG-B.

Optionally, the manner in which the transmitter 30 sends downlink OFDMAdata information to each terminal on a subchannel corresponding to theterminal may be implemented by building an inverse discrete Fouriertransform (IDFT) module corresponding to an antenna of the access pointin the transmitter 30, that is, the access point may first performencoding, space stream separation and space-time encoding on downlinkdata of multiple terminals into multiple space-time streams, andreference may be made to FIG. 28. The space-time streams correspond tothe antenna of the access point. Space-time streams of differentterminals on a same antenna are mapped, by using an IDFT modulecorresponding to the antenna, to subchannels or subcarrierscorresponding to the terminals and sent, thereby sending respectivecorresponding downlink OFDMA data information to the terminals by usingdifferent subchannels. If the access point is provided with multipleantennas, there are a corresponding quantity of IDFT modules (if aquantity of antennas is M, a quantity of IDFT modules is also M). TheseIDFT modules all work on a same frequency band. Therefore, for OFDMA inwhich the access point is provided with multiple antennas, differentusers work on different subchannels; and on a same subchannel,space-time streams of the access point may be distinguished by means ofspace mapping. The space-time streams may further support MU-MIMOimplementation on the subchannel.

Correspondingly, a terminal performs demodulation by using a discreteFourier transform (DFT) module to obtain data of a receiving end, andobtains, according to an indication of OFDMA physical layer signaling,data on a subchannel on which the terminal is located. If the data ismulti-antenna space mapping signals, the signals are separated by usingmultiple antennas; or if the data is single-antenna signals, the signalsdo not need to be separated.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

FIG. 29 is a schematic structural diagram of Embodiment 4 of an accesspoint according to the present invention. The access point includes theforegoing transmitter 30, and further includes a receiver 31.

The foregoing OFDMA physical layer signaling or the foregoing downlinkOFDMA data information carries an OFDMA ACK request or an OFDMA BArequest, and the OFDMA ACK request or the OFDMA BA request is used forinstructing the terminal to send an ACK response or a BA response to theaccess point in the OFDMA mode; then the foregoing OFDMA physical layersignaling is further used for indicating the subchannel that correspondsto the terminal, on which the ACK response or the BA response is sent tothe access point and that is allocated for the terminal; and then thereceiver 31 is configured to: after the transmitter 30 sends thedownlink OFDMA data information on the subchannel corresponding to theterminal in the OFDMA mode, receive the ACK response or the BA responsethat is sent by the terminal on the subchannel corresponding to theterminal in the OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

Optionally, the OFDMA physical layer signaling is used for indicatingthe subchannel that corresponds to the terminal, on which the ACKresponse or the BA response is sent to the access point and that isallocated for the terminal; and then the transmitter 30 may be furtherconfigured to: after the downlink OFDMA data information is sent on thesubchannel corresponding to the terminal, send an ACK request frame or aBA request frame to the terminal, where the ACK request frame or the BArequest frame includes a dedicated information bit, and the dedicatedinformation bit is used for instructing the terminal to send the ACKresponse or the BA response to the access point in the OFDMA mode; andthe receiver 31 may be further configured to receive the ACK response orthe BA response that is sent by the terminal on the correspondingsubchannel in the OFDMA mode.

Optionally, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the transmitter 30 is specificallyconfigured to send MU-MIMO data information to the terminal in a MU-MIMOmode, where the MU-MIMO data information carries OFDMA physical layersignaling; the receiver 31 may be further configured to: after thetransmitter 30 sends the OFDMA physical layer signaling to the terminal,receive the ACK response or the BA response that is sent by the terminalon the corresponding subchannel in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thetransmitter 30 is specifically configured to send MU-MIMO datainformation to the terminal in a MU-MIMO mode, where the MU-MIMO datainformation carries OFDMA physical layer signaling; and send an ACKrequest frame or a BA request frame to the terminal, where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode; and the receiver 31 may be further configured to:after the transmitter sends the OFDMA physical layer signaling to theterminal, receive the ACK response or the BA response that is sent bythe terminal on the corresponding subchannel in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thetransmitter 30 is specifically configured to send MU-MIMO datainformation to the terminal in a MU-MIMO mode; and send an ACK requestframe or a BA request frame to the terminal, where the ACK request frameor the BA request frame includes a dedicated information bit, and thededicated information bit is used for instructing the terminal to sendthe ACK response or the BA response to the access point in the OFDMAmode; and the ACK request frame or the BA request frame carries theOFDMA physical layer signaling; and the receiver 31 may be furtherconfigured to: after the transmitter 30 sends the OFDMA physical layersignaling to the terminal, receive the ACK response or the BA responsethat is sent by the terminal on the corresponding subchannel in theOFDMA mode.

Optionally, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and the transmitter 30 may be furtherconfigured to: after the OFDMA physical layer signaling is sent to theterminal, send OFDMA+MU-MIMO data information to the terminal on thesubchannel corresponding to the terminal in an OFDMA+MU-MIMO mode; andthe receiver 31 may be further configured to receive the ACK response orthe BA response that is sent by the terminal on the correspondingsubchannel in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thetransmitter 30 is further configured to: after the OFDMA physical layersignaling is sent to the terminal, send OFDMA+MU-MIMO data informationto the terminal on the subchannel corresponding to the terminal in anOFDMA+MU-MIMO mode; and send an ACK request frame or a BA request frameto the terminal, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and the receiver 31 maybe further configured to receive the ACK response or the BA responsethat is sent by the terminal on the corresponding subchannel in theOFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the receiver 31may be further configured to: before the transmitter 30 sends the OFDMAphysical layer signaling to the terminal, receive an uplink transmissionframe sent by the terminal; and after the transmitter 30 sends the OFDMAphysical layer signaling to the terminal, receive the uplink OFDMA datainformation that is sent by the terminal on the corresponding subchannelin an OFDMA mode. Optionally, the transmitter 30 may further transmituplink OFDMA data information by using an IDFT module, so that eachterminal may learns, according to the OFDMA physical layer signaling, apart corresponding to the terminal in a subchannel or subcarrier mappedonly by using the IDFT module, and set other parts to 0, and referencemay be made to FIG. 30.

Optionally, the uplink OFDMA data information carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is further used for instructing the access point to send anACK response or a BA response to the terminal in the OFDMA mode; andthen the transmitter 30 is further configured to: after the receiver 31receives the uplink OFDMA data information that is sent by the terminalon the corresponding subchannel, send the ACK response or the BAresponse corresponding to the uplink OFDMA data information on thesubchannel corresponding to the terminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the receiver 31is further configured to: after the transmitter 30 sends the OFDMAphysical layer signaling to the terminal, receive the uplink OFDMA datainformation that is sent by the terminal on the corresponding subchannelin an OFDMA mode.

The access point provided in this embodiment of the present inventionmay perform the technical solutions of the embodiments of the foregoingdata transmission indication methods, whose implementation principlesand technical effects are similar, and details are not described hereinagain.

FIG. 31 is a schematic structural diagram of Embodiment 4 of a terminalaccording to the present invention. As shown in FIG. 31, the terminalincludes: a receiver 40 and a processor 41.

The receiver 40 is configured to receive OFDMA physical layer signalingsent by an access point, where the OFDMA physical layer signaling isused for indicating, to the terminal, a subchannel allocated by theaccess point for the terminal, where the OFDMA physical layer signalingincludes an identifier of the terminal and subchannel informationcorresponding to the identifier of the terminal.

The processor 41 is configured to determine a subchannel correspondingto the terminal according to the OFDMA physical layer signaling.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Optionally, the identifier of the terminal is an identifier of one ormore terminal groups, and each terminal group includes at least oneterminal; and then the OFDMA physical layer signaling being used forindicating, to the terminal, a subchannel allocated for the terminalincludes: the OFDMA physical layer signaling being used for indicatingto each terminal group that the allocated subchannel is an uplinksubchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminal groups and subchannels are in aone-to-one correspondence.

The receiver 40 may be further configured to: before the OFDMA physicallayer signaling sent by the access point is received, receive a mappingrelationship between an identifier of the terminal group and an addressof the terminal, where the mapping relationship is sent by the accesspoint; and then the processor 41 is specifically configured to determineaccording to the mapping relationship that the terminal is located inthe terminal group, and then determine that a subchannel correspondingto the terminal group is the subchannel corresponding to the terminal.

Optionally, the identifier of the terminal is an identifier of oneterminal group, and the terminal group includes at least two terminals;and then the OFDMA physical layer signaling being used for indicating,to the terminal, a subchannel allocated for the terminal includes: theOFDMA physical layer signaling being used for indicating to eachterminal in the terminal group that the allocated subchannel is anuplink subchannel or a downlink subchannel or an uplink and downlinkbidirectional subchannel, where terminals in the terminal group andsubchannels are in a one-to-one correspondence.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Further, the receiver 40 is specifically configured to receive an OFDMpreamble sent by the access point, where the OFDM preamble carries theOFDMA physical layer signaling.

Optionally, the receiver 40 may be further configured to receive a NDPAframe sent by the access point, where the NDPA frame carries theforegoing OFDMA physical layer signaling.

Optionally, the receiver 40 may be further configured to receive an NDPAframe and an OFDM preamble that are sent by the access point, where theNDPA frame carries the identifier of the terminal in the OFDMA physicallayer signaling, and the OFDM preamble carries the subchannelinformation corresponding to the identifier of the terminal and being inthe OFDMA physical layer signaling.

Optionally, the receiver 40 may be further configured to receive an NDPAframe and an OFDM preamble that are sent by the access point, where theNDPA frame carries subchannel information corresponding to an identifierof the terminal and being in the foregoing OFDMA physical layersignaling, and the OFDM preamble carries the identifier of the terminalin the foregoing OFDMA physical layer signaling.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Further, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, a subchannel that is allocated by theaccess point to the terminal for receiving downlink OFDMA data, and thenthe receiver 40 is further configured to: after the processor 41determines the subchannel corresponding to the terminal according to theOFDMA physical layer signaling, receive, on the subchannel correspondingto the terminal, downlink OFDMA data information sent by the accesspoint, where the downlink OFDMA data information includes an OFDMApreamble and OFDMA data, and the OFDMA preamble includes a switchingfield and UHT-SIG-B.

Further, the receiver 40 is specifically configured to receive adestination terminal address corresponding to the OFDMA data and sent bythe access point; determine whether the terminal matches the destinationterminal address; and if yes, receive, on the subchannel correspondingto the terminal, downlink OFDMA data information sent by the accesspoint.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

FIG. 32 is a schematic structural diagram of Embodiment 5 of a terminalaccording to the present invention. On the basis of the embodiment shownin FIG. 31, further, the terminal further includes a transmitter 42.

Optionally, the foregoing OFDMA physical layer signaling or theforegoing downlink OFDMA data information carries an OFDMA ACK requestor an OFDMA BA request, and the OFDMA ACK request or the OFDMA BArequest is used for instructing the terminal to send an ACK response ora BA response to the access point in the OFDMA mode; then the foregoingOFDMA physical layer signaling is further used for indicating thesubchannel that corresponds to the terminal, on which the ACK responseor the BA response is sent to the access point and that is allocated forthe terminal; and then the transmitter 42 is configured to: after thereceiver 40 receives, on the subchannel corresponding to the terminal,the downlink OFDMA data information sent by the access point, send theACK response or the BA response to the access point on the subchannelcorresponding to the terminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is further used forindicating the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and the receiver 40 may be furtherconfigured to: after the downlink OFDMA data information sent by theaccess point is received on the subchannel corresponding to theterminal, receive an ACK request frame or a BA request frame sent by theaccess point, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and the transmitter 42is configured to send the ACK response or the BA response to the accesspoint on the subchannel corresponding to the terminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the receiver 40 may be furtherconfigured to receive MU-MIMO data information sent by the access point,where the MU-MIMO data information carries the OFDMA physical layersignaling; and the transmitter 42 is configured to: after the processor41 determines the subchannel corresponding to the terminal according tothe OFDMA physical layer signaling, send the ACK response or the BAresponse to the access point on the subchannel corresponding to theterminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thereceiver 40 may be further configured to receive MU-MIMO datainformation sent by the access point, where the MU-MIMO data informationcarries the OFDMA physical layer signaling; and receive an ACK requestframe or a BA request frame sent by the access point, where the ACKrequest frame or the BA request frame includes a dedicated informationbit, and the dedicated information bit is used for instructing theterminal to send the ACK response or the BA response to the access pointin the OFDMA mode; and

the transmitter 42 is configured to: after the processor 41 determinesthe subchannel corresponding to the terminal according to the OFDMAphysical layer signaling, send the ACK response or the BA response tothe access point on the subchannel corresponding to the terminal in theOFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thereceiver 40 may be further configured to receive MU-MIMO datainformation sent by the access point, and receive an ACK request frameor a BA request frame sent by the access point, where the ACK requestframe or the BA request frame includes a dedicated information bit, andthe dedicated information bit is used for instructing the terminal tosend the ACK response or the BA response to the access point in theOFDMA mode; and the ACK request frame or the BA request frame carriesthe OFDMA physical layer signaling; and then the transmitter 42 isconfigured to: after the processor 41 determines the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, send the ACK response or the BA response to the access pointon the subchannel corresponding to the terminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is used for instructing the terminal to send an ACK responseor a BA response to the access point in an OFDMA mode; then the OFDMAphysical layer signaling is specifically used for indicating, to theterminal, the subchannel that corresponds to the terminal, on which theACK response or the BA response is sent to the access point and that isallocated for the terminal; and then the receiver 40 may be furtherconfigured to: after the processor 41 determines the subchannelcorresponding to the terminal according to the OFDMA physical layersignaling, receive, on the subchannel corresponding to the terminal,OFDMA+MU-MIMO data information sent by the access point; and thetransmitter 42 is configured to send the ACK response or the BA responseto the access point on the subchannel corresponding to the terminal inthe OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which the ACK response or the BA response is sent to theaccess point and that is allocated for the terminal; and then thereceiver 40 may be further configured to: after the processor 41determines the subchannel corresponding to the terminal according to theOFDMA physical layer signaling, receive, on the subchannel correspondingto the terminal, OFDMA+MU-MIMO data information sent by the accesspoint; and receive an ACK request frame or a BA request frame sent bythe access point, where the ACK request frame or the BA request frameincludes a dedicated information bit, and the dedicated information bitis used for instructing the terminal to send the ACK response or the BAresponse to the access point in the OFDMA mode; and the transmitter 42is configured to send the ACK response or the BA response to the accesspoint on the subchannel corresponding to the terminal in the OFDMA mode.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel on which uplink OFDMA datainformation is sent to the access point and that is allocated for theterminal; and then the transmitter 42 may be further configured to:before the receiver 40 receives the OFDMA physical layer signaling sentby the access point, send an uplink transmission frame to the accesspoint; and may be further configured to: after the processor 41determines the subchannel corresponding to the terminal according to theOFDMA physical layer signaling, send the uplink OFDMA data informationto the access point on the subchannel corresponding to the terminal inthe OFDMA mode.

Optionally, the uplink OFDMA data information carries an OFDMA ACKrequest or an OFDMA BA request, and the OFDMA ACK request or the OFDMABA request is further used for instructing the access point to send anACK response or a BA response to the terminal in the OFDMA mode; andthen the receiver 40 may be further configured to: after the transmitter42 sends the uplink OFDMA data information to the access point, receive,on the subchannel corresponding to the terminal, the ACK response or theBA response corresponding to the uplink OFDMA data information and sentby the access point.

Optionally, the OFDMA physical layer signaling is specifically used forindicating, to the terminal, the subchannel that corresponds to theterminal, on which uplink OFDMA data information is sent to the accesspoint and that is allocated for the terminal; and then the transmitter42 may be further configured to: after the processor 41 determines thesubchannel corresponding to the terminal according to the OFDMA physicallayer signaling, send the uplink OFDMA data information to the accesspoint on the subchannel corresponding to the terminal in the OFDMA mode.

The terminal provided in this embodiment of the present invention mayperform the technical solutions of the embodiments of the foregoing datatransmission indication methods, whose implementation principles andtechnical effects are similar, and details are not described hereinagain.

Finally, it should be noted that the foregoing embodiments are merelyintended for describing the technical solutions of the presentinvention, but not for limiting the present invention. Although thepresent invention is described in detail with reference to the foregoingembodiments, persons of ordinary skill in the art should understand thatthey may still make modifications to the technical solutions describedin the foregoing embodiments or make equivalent replacements to some orall technical features thereof, without departing from the scope of thetechnical solutions of the embodiments of the present invention.

The invention claimed is:
 1. A data transmission indication method,comprising: sending, by an access point, an orthogonal frequencydivision multiple access (OFDMA) physical layer signaling to a terminal,by using orthogonal frequency division multiplexing (OFDM), wherein theOFDMA physical layer signaling indicates, to the terminal, a firstsubchannel allocated to the terminal for receiving a downlink OFDMA datainformation; sending, by the access point using OFDMA, the downlinkOFDMA data information on the first subchannel allocated to theterminal, wherein the downlink OFDMA data information comprising: afirst part instructing the terminal to send a response of the downlinkOFDMA data information to the access point by using OFDMA, wherein theresponse is one of an ACK response or a BA response; and a second partindicating a second subchannel allocated to the terminal for sending theresponse to the access point by using OFDMA in accordance with the firstpart instructing to use OFDMA; and receiving, by the access point, theresponse sent by the terminal by using OFDMA on the second subchannel.2. The method according to claim 1, further comprising: receiving, bythe access point, an uplink OFDMA data information from the terminal onthe second subchannel by using OFDMA.
 3. The method according to claim1, wherein a channel bandwidth is one or more 20 MHz, the quantity ofsubcarriers of the channel bandwidth by using OFDMA is K multiples ofthe quantity of subcarriers of the channel bandwidth by using OFDM, K isan integer.
 4. The method according to claim 3, wherein the quantity ofsubcarriers by using OFDMA is 64*K per 20 MHz.
 5. The method accordingto claim 1, where the first subchannel and the second subchannel includeone or more subcarriers respectively.
 6. The method according to claim1, wherein the OFDMA physical layer signaling comprises an identifier ofthe terminal and information of the first subchannel.
 7. A networkapparatus that acts as an access point, comprising: a transmitter; areceiver; a processor; and a non-transitory computer readable mediumcomprising computer-executable instructions that, when executed by theprocessor, facilitate performing a method wherein the transmitter andreceiver cooperatively operate with the processor to: send, by thetransmitter cooperatively operating with the processor and usingorthogonal frequency division multiplexing (OFDM), an orthogonalfrequency division multiple access (OFDMA) physical layer signaling to aterminal, wherein the OFDMA physical layer signaling indicates, to theterminal, a first subchannel allocated to the terminal for receiving adownlink OFDMA data information; send, by the transmitter cooperativelyoperating with the processor and using OFDMA, the downlink OFDMA datainformation on the first subchannel allocated to the terminal, whereinthe downlink OFDMA data information comprising: a first part instructingthe terminal to send a response of the downlink OFDMA data informationto the access point by using OFDMA, wherein the response is one of anACK response or a BA response; and a second part indicating a secondsubchannel allocated to the terminal for sending the response to theaccess point by using OFDMA in accordance with the first partinstructing to use OFDMA; and receive, by the receiver cooperativelyoperating with the processor and using OFDMA, the response sent by theterminal by using OFDMA on the second subchannel.
 8. The networkapparatus according to claim 7, wherein: the receiver is furtherconfigured to receive, by using OFDMA, an uplink OFDMA data informationfrom the terminal on the second subchannel.
 9. The network apparatusaccording to claim 7, wherein a channel bandwidth is one or more 20 MHz,the quantity of subcarriers of the channel bandwidth by using OFDMA is Kmultiples of the quantity of subcarriers of the channel bandwidth byusing OFDM, K is an integer.
 10. The network apparatus according toclaim 9, wherein the quantity of subcarriers by using OFDMA is 64*K per20 MHz.
 11. The network apparatus according to claim 7, where the firstsubchannel and the second subchannel include one or more subcarriersrespectively.
 12. The network apparatus according to claim 7, whereinthe OFDMA physical layer signaling comprises an identifier of theterminal and information of the first subchannel.
 13. A datatransmission indication method, comprising: receiving, by a terminal, anorthogonal frequency division multiple access (OFDMA) physical layersignaling from an access point, wherein the OFDMA physical layersignaling indicates, to the terminal, a first subchannel allocated tothe terminal for receiving a downlink OFDMA data information; receiving,by the terminal, the downlink OFDMA data information on the firstsubchannel allocated to the terminal, wherein the downlink OFDMA datainformation comprising: a first part instructing the terminal to send aresponse of the downlink OFDMA data information to the access point byusing OFDMA, wherein the response is one of an ACK response or a BAresponse; and a second part indicating a second subchannel allocated tothe terminal for sending the response to the access point by using OFDMAin accordance with the first part instructing to use OFDMA; and sending,by the terminal by using OFDMA, the response to the access point on thesecond subchannel.
 14. The method according to claim 13, furthercomprising: sending, by the terminal, an uplink OFDMA data informationto the access point on the second subchannel by using OFDMA.
 15. Themethod according to claim 13, wherein a channel bandwidth is one or more20 MHz, the quantity of subcarriers of the channel bandwidth by usingOFDMA is K multiples of the quantity of subcarriers of the channelbandwidth by using OFDM, K is an integer.
 16. The method according toclaim 15, wherein the quantity of subcarriers by using OFDMA is 64*K per20 MHz.
 17. The method according to claim 13, where the first subchanneland the second subchannel include one or more subcarriers respectively.18. The method according to claim 13, wherein the OFDMA physical layersignaling comprises an identifier of the terminal and information of thefirst subchannel.
 19. A network apparatus that acts as a terminal,comprising: a transmitter; a receiver; a processor; and a non-transitorycomputer readable medium comprising computer-executable instructionsthat, when executed by the processor, facilitate performing a methodwherein the transmitter and receiver cooperatively operate with theprocessor to: receive, by the receiver cooperatively operating with theprocessor, an orthogonal frequency division multiple access (OFDMA)physical layer signaling from an access point, wherein the OFDMAphysical layer signaling indicates, to the terminal, a first subchannelallocated to the terminal for receiving a downlink OFDMA datainformation; receive, by the receiver cooperatively operating with theprocessor, the downlink OFDMA data information on the first subchannelallocated to the terminal, wherein the downlink OFDMA data informationcomprising: a first part instructing the terminal to send a response ofthe downlink OFDMA data information to the access point by using OFDMA,wherein the response is one of an ACK response or a BA response; and asecond part indicating a second subchannel allocated to the terminal forsending the response to the access point by using OFDMA in accordancewith the first part instructing to use OFDMA; and send, by thetransmitter cooperatively operating with the processor and using OFDMA,the response to the access point on the second subchannel.
 20. Thenetwork apparatus according to claim 19, wherein: the transmitter isfurther configured to send, by using OFDMA, an uplink OFDMA datainformation to the access point on the second subchannel.
 21. Thenetwork apparatus according to claim 19, wherein a channel bandwidth isone or more 20 MHz, the quantity of subcarriers of the channel bandwidthby using OFDMA is K multiples of the quantity of subcarriers of thechannel bandwidth by using OFDM, K is an integer.
 22. The networkapparatus according to claim 21, wherein the quantity of subcarriers byusing OFDMA is 64*K per 20 MHz.
 23. The network apparatus according toclaim 19, where the first subchannel and the second subchannel includeone or more subcarriers respectively.
 24. The method according to claim19, wherein the OFDMA physical layer signaling comprises an identifierof the terminal and information of the first subchannel.